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Sample records for nuclear log

  1. Nuclear well logging in hydrology

    International Nuclear Information System (INIS)

    1971-01-01

    The optimum development of regional and local groundwater resources requires a quantitative evaluation of its aquifers and aquicludes, and of the physical and chemical properties relevant to the recharge to and withdrawal of water from them. If an understanding of the groundwater regime is to be obtained, geological observations at outcrop must be augmented by subsurface measurements of the strata and the waters they contain. Measurements of many hydrological and geological parameters can be made in situ by nuclear geophysical well-logging methods. Very simply, well logging consists of lowering a measuring probe into a well and making a continuous record of the variations of a particular parameter with depth. In most circumstances, repetition of the measurements under differing hydrodynamic conditions results in a better definition of the flow regime in the aquifer. Nuclear well-logging techniques have for some years been capable of solving a number of the sub-surface measurement problems faced by hydrogeologists. However, the present usage of these methods varies from country to country and the literature concerning applications is scattered in the professional journals of several disciplines. The objective of this report is to include in a single reference volume descriptions of the physical principles of nuclear logging methods, their applications to hydrogeological problems and their limitations on a level suitable for the practising hydrologists with a limited knowledge of nuclear physics. The Working Group responsible for compiling the report recommended that it should cover a broad spectrum of hydrogeological investigations and problems. For example, it saw no valid reason to distinguish for the purposes of the report between well-logging applications for water-supply purposes and for water-flooding studies in the petroleum industry. Neutron measurements made for soil-moisture determinations in the unsaturated zone have been specifically omitted, however, as

  2. The nuclear magnetic resonance well logging

    International Nuclear Information System (INIS)

    Zhang Yumin; Shen Huitang

    2003-01-01

    In this paper, the characteristic of the nuclear magnetic resonance logging is described at first. Then its development and its principle is presented. Compared with the nuclear magnetic resonance spectrometer, the magnet techniques is the first question that we must solve in the manufacture of the NMR well logging

  3. Model wells for nuclear well logging

    International Nuclear Information System (INIS)

    Tittle, C.W.

    1989-01-01

    Considerations needed in the design and construction of model wells for nuclear log calibration are covered, with special attention to neutron porosity logging and total γ-ray logging. Pulsed neutron decay-time and spectral γ-ray logging are discussed briefly. The American Petroleum Institute calibration facility for nuclear logs is a good starting point for similar or expanded facilities. A few of its shortcomings are mentioned; they are minor. The problem of fluid saturation is emphasized. Attention is given to models made of consolidated rock and those containing unconsolidated material such as Ottawa sand. Needed precautions are listed. A similarity method is presented for estimating the porosity index of formations that are not fully saturated. (author)

  4. Nuclear log interpretation by first principle

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1988-07-01

    A weakness connected to the present interpretation of nuclear borehole logs is that the interdependence of the various logs and physical effects of importance for the tools are not always taken into account in a correct way. Therefore a new approach to the interpretation of nuclear borehole logs is considered. It is based on the logs obtained with the natural gamma, the neutron porosity, the gamma density, and the pulsed neutron tools. For each of these tools a model, taking into account the important physical effects, is established. These models are incorporated into a computer programme which from the tool signals calculates, by use of iteration, a consistent set of the corresponding formation properties. In the paper the models developed for the four tools and the interpretation programme are briefly described. An example of the use of the interpretation programme is given and compared with a conventional interpretation. (author)

  5. Nuclear borehole logging for oil exploration

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1989-01-01

    Reactor physics can be applied to the logging of boreholes for the exploration of oil and gas and the results obtained can be interpreted more correctly by use of reactor physics models, e.g. one-dimensional multi-group diffusion theory adapted for gamma quanta. The standard nuclear logging tools are: natural gamma, gamma density, neutron porosity and the pulsed-neutron tool. The models and interpretation procedures are discussed. 1 fig

  6. Comparative analysis of nuclear magnetic resonance well logging and nuclear magnetic resonance mud logging

    International Nuclear Information System (INIS)

    Yuan Zugui

    2008-01-01

    The hydrogen atoms in oil and water are able to resonate and generate signals in the magnetic field, which is used by the NMR (nuclear magnetic resonance) technology in petroleum engineering to research and evaluate rock characteristics. NMR well logging was used to measure the physical property parameters of the strata in well bore, whereas NMR mud logging was used to analyze (while drilling) the physical property parameters of cores, cuttings and sidewall coring samples on surface (drilling site). Based on the comparative analysis of the porosity and permeability parameters obtained by NMR well logging and those from analysis of the cores, cuttings and sidewall coring samples by NMR mud logging in the same depth of 13 wells, these two methods are of certain difference, but their integral tendency is relatively good. (authors)

  7. Water injection profiling by nuclear logging

    International Nuclear Information System (INIS)

    Arnold, D.M.

    1980-01-01

    This invention relates to nuclear logging techniques for determining the volume flow rates and flow directions of injected water moving behind a wellbore casing. The apparatus includes a sonde equipped with a neutron source and dual radiation detectors. Oxygen in the neutron irradiated water is transmitted to 16 N and the resultant primary and Compton scattered gamma rays are detected in two energy windows by both detectors. Count rate data is analysed in terms of the windows to obtain linear flow velocities for water flow within and behind the casing. Volume flow rates are determined for upward and downward flow, and horizontal volume flow into the surrounding formation is calculated. A complete injection profile may thus be obtained. (U.K.)

  8. MCNP capabilities for nuclear well logging calculations

    International Nuclear Information System (INIS)

    Forster, R.A.; Little, R.C.; Briesmeister, J.F.; Hendricks, J.S.

    1990-01-01

    The Los Alamos Radiation Transport Code System (LARTCS) consists of state-of-the-art Monte Carlo and discrete ordinates transport codes and data libraries. This paper discusses how the general-purpose continuous-energy Monte Carlo code MCNP (Monte Carlo neutron photon), part of the LARTCS, provides a computational predictive capability for many applications of interest to the nuclear well logging community. The generalized three-dimensional geometry of MCNP is well suited for borehole-tool models. SABRINA, another component of the LARTCS, is a graphics code that can be used to interactively create a complex MCNP geometry. Users can define many source and tally characteristics with standard MCNP features. The time-dependent capability of the code is essential when modeling pulsed sources. Problems with neutrons, photons, and electrons as either single particle or coupled particles can be calculated with MCNP. The physics of neutron and photon transport and interactions is modeled in detail using the latest available cross-section data

  9. A history of nuclear well logging in the oil industry

    International Nuclear Information System (INIS)

    Tittle, C.W.

    1989-01-01

    Spurred by an interest in logging through steel casing γ-ray logging began in the late 1930s followed soon by neutron logging for porosity. These were the first two nuclear well logs. Gamma-gamma density logging was developed during the 1950s. Pulsed neutron lifetime logging appeared in the 1960s; the slim tools came in the early 1970s. Developments since then have included dual detector devices of several types which offered improved measurements or interpretation, γ-ray spectrometry logging (natural and neutron-induced) which identifies certain chemical elements, induced radioactivity logging, and the photoelectric absorption log, which, combined with the density log in a single tool, is known as litho-density logging. A combination of several γ-ray spectrometers in one tool, designed to determine 10 formation elements, was recently introduced, and a new neutron porosity tool measuring epithermal neutron die-away time has been developed. Digital transmission of logging data was a step forward in about 1975. Also, log interpretation techniques have greatly expanded since the advent of digital computers, and the microcomputer has had a distinct impact. It is now practical and economical to do iterative analysis on a suite of logs to obtain an optimum overall interpretation. (author)

  10. The analog CTS communication interface in nuclear logging

    International Nuclear Information System (INIS)

    Li Min

    2000-01-01

    The author introduced a micro-controller-based CTS communication interface in nuclear logging, which provided convenience for the overhaul and regulation of the logging tool in CTS communication system. The use of micro-controller simplified the hardware structure of the interface, made the soft structure more rational and the whole system more flexible to control

  11. Monte Carlo Numerical Models for Nuclear Logging Applications

    Directory of Open Access Journals (Sweden)

    Fusheng Li

    2012-06-01

    Full Text Available Nuclear logging is one of most important logging services provided by many oil service companies. The main parameters of interest are formation porosity, bulk density, and natural radiation. Other services are also provided from using complex nuclear logging tools, such as formation lithology/mineralogy, etc. Some parameters can be measured by using neutron logging tools and some can only be measured by using a gamma ray tool. To understand the response of nuclear logging tools, the neutron transport/diffusion theory and photon diffusion theory are needed. Unfortunately, for most cases there are no analytical answers if complex tool geometry is involved. For many years, Monte Carlo numerical models have been used by nuclear scientists in the well logging industry to address these challenges. The models have been widely employed in the optimization of nuclear logging tool design, and the development of interpretation methods for nuclear logs. They have also been used to predict the response of nuclear logging systems for forward simulation problems. In this case, the system parameters including geometry, materials and nuclear sources, etc., are pre-defined and the transportation and interactions of nuclear particles (such as neutrons, photons and/or electrons in the regions of interest are simulated according to detailed nuclear physics theory and their nuclear cross-section data (probability of interacting. Then the deposited energies of particles entering the detectors are recorded and tallied and the tool responses to such a scenario are generated. A general-purpose code named Monte Carlo N– Particle (MCNP has been the industry-standard for some time. In this paper, we briefly introduce the fundamental principles of Monte Carlo numerical modeling and review the physics of MCNP. Some of the latest developments of Monte Carlo Models are also reviewed. A variety of examples are presented to illustrate the uses of Monte Carlo numerical models

  12. Opportunities to reduce risk associated with nuclear logging techniques

    International Nuclear Information System (INIS)

    Wraight, P.D.; Robinson, E.; de Fleurieu, R.

    1991-01-01

    Nuclear logging provides petroleum exploration and production companies with data that are critical to their decisions and operations. Because this type data is so important, environmentally conscious well-logging and service companies are constantly reviewing the risks to people and environment associated with nuclear sources with the ALARA (as low as reasonably achievable) principle in mind. Opportunities to additionally reduce risks, which can be accomplished only with the active involvement of oil companies, are proposed in this paper

  13. Physical and measuring principles of nuclear well logging techniques

    International Nuclear Information System (INIS)

    Loetzsch, U.; Winkler, R.

    1981-01-01

    Proceeding from the general task of nuclear geophysics as a special discipline of applied geophyscis, the essential physical problems of nuclear well logging techniques are considered. Particularly, the quantitative relationship between measured values and interesting geologic parameters to be determined are discussed taking into account internal and external perturbation parameters. Resulting from this study, the technological requirements for radiation sources and their shielding, for detectors, electronic circuits in logging tools, signal transmission by cable and recording equipment are derived, and explained on the basis of examples of gamma-gamma and neutron-neutron logging. (author)

  14. Acoustic--nuclear permeability logging system

    International Nuclear Information System (INIS)

    Dowling, D.J.; Arnold, D.M.

    1978-01-01

    A down hole logging tool featuring a neutron generator, an acoustic disturbance generator, and a radiation detection system is described. An array of acoustic magnetostriction transducers is arranged about the target of a neutron accelerator. Two gamma ray sensors are separated from the accelerator target by shielding. According to the method of the invention, the underground fluid at the level of a formation is bombarded by neutrons which react with oxygen in the fluid to produce unstable nitrogen 16 particles according to the reaction 16 O(n,p) 16 N. Acoustic pulses are communicated to the fluid, and are incident on the boundary of the borehole at the formation. The resulting net flow of fluid across the boundary is determined from radiation detection measurements of the decaying 16 N particles in the fluid. A measure of the permeability of the formation is obtained from the determination of net fluid flow across the boundary

  15. Radiation transport methods for nuclear log assessment - an overview

    International Nuclear Information System (INIS)

    Badruzzaman, A.

    1996-01-01

    Methods of radiation transport have been applied to well-logging problems with nuclear sources since the early 1960s. Nuclear sondes are used in identifying rock compositions and fluid properties in reservoirs to predict the porosity and oil saturation. Early computational effort in nuclear logging used diffusion techniques. As computers became more powerful, deterministic transport methods and, finally, Monte Carlo methods were applied to solve these problems in three dimensions. Recently, the application has been extended to problems with a new generation of devices, including spectroscopic sondes that measure such quantities as the carbon/oxygen ratio to predict oil saturation and logging-while-drilling (LWD) sondes that take neutron and gamma measurements as they rotate in the borehole. These measurements present conditions that will be difficult to calibrate in the laboratory

  16. Nuclear data for geophysical spectroscopic logging

    International Nuclear Information System (INIS)

    Schweitzer, J.S.; Hertzog, R.C.; Soran, P.D.

    1987-01-01

    Nuclear geochemical analysis requires the quantitative measurement of elemental concentrations of trace elements, as well as major elements in widely varying concentrations. This requirement places extreme demands on the quality of the spectroscopic measurements, data rates, and relating observed γ-ray intensities to the original elemental concentration. The relationship between γ-ray intensities and elemental concentration is critically dependent on the specific reaction cross sections and their uncertainties. The elements of highest priority for subsurface geochemical analysis are considered with respect to the importance of competing reactions and the neutron energy regions that are most significant. (author)

  17. Application of nuclear logging to porosity studies in Itaborai basin

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Milena F.S.; Lima, Inaya; Lopes, Ricardo Tadeu, E-mail: milena@lin.ufrj.br, E-mail: inaya@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Ferrucio, Paula Lucia; Borghi, Leonardo, E-mail: ferrucio@acd.ufrj.br, E-mail: borghi@ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Geociencias. Dept. de Geologia; Abreu, Carlos Jorge, E-mail: jo_abreu@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Geociencias

    2011-07-01

    Nuclear logging provides information on bulk density and porosity variations by measuring the intensity of the scattered radiation induced on the formation by radioactive sources. In this study, nuclear logging was employed to analyze the pore-space system of the 2-ITAB-1-RJ well placed on the Itaborai limestone basin, in the state of Rio de Janeiro. This is one of the smallest sedimentary basin in Brazil and it is formed by clastic deposits and travertine limestone rocks which are fractured. Understanding the pore-space system of carbonate rocks has become important subject for the oil industry, specially in Brazil. A Density Gamma Probe (LSD) and a Neutron Probe (NEUT) were used for data acquisition, which nuclear logging was carried out in part of the well, with continuous detection for about 50 m of deep. The detection speed was 4 m/min for the LSD and 5 m/min for the NEUT. The results obtained by nuclear logging showed that the 2-ITAB-1-RJ well consists of three different intervals with rocks ranging from low to moderate porosity present in travertine, marls and gneisses. (author)

  18. Nuclear Well Log Properties of Natural Gas Hydrate Reservoirs

    Science.gov (United States)

    Burchwell, A.; Cook, A.

    2015-12-01

    Characterizing gas hydrate in a reservoir typically involves a full suite of geophysical well logs. The most common method involves using resistivity measurements to quantify the decrease in electrically conductive water when replaced with gas hydrate. Compressional velocity measurements are also used because the gas hydrate significantly strengthens the moduli of the sediment. At many gas hydrate sites, nuclear well logs, which include the photoelectric effect, formation sigma, carbon/oxygen ratio and neutron porosity, are also collected but often not used. In fact, the nuclear response of a gas hydrate reservoir is not known. In this research we will focus on the nuclear log response in gas hydrate reservoirs at the Mallik Field at the Mackenzie Delta, Northwest Territories, Canada, and the Gas Hydrate Joint Industry Project Leg 2 sites in the northern Gulf of Mexico. Nuclear logs may add increased robustness to the investigation into the properties of gas hydrates and some types of logs may offer an opportunity to distinguish between gas hydrate and permafrost. For example, a true formation sigma log measures the thermal neutron capture cross section of a formation and pore constituents; it is especially sensitive to hydrogen and chlorine in the pore space. Chlorine has a high absorption potential, and is used to determine the amount of saline water within pore spaces. Gas hydrate offers a difference in elemental composition compared to water-saturated intervals. Thus, in permafrost areas, the carbon/oxygen ratio may vary between gas hydrate and permafrost, due to the increase of carbon in gas hydrate accumulations. At the Mallik site, we observe a hydrate-bearing sand (1085-1107 m) above a water-bearing sand (1107-1140 m), which was confirmed through core samples and mud gas analysis. We observe a decrease in the photoelectric absorption of ~0.5 barnes/e-, as well as an increase in the formation sigma readings of ~5 capture units in the water-bearing sand as

  19. Nuclear logging apparatus and MWD-equipment for formation evaluation

    International Nuclear Information System (INIS)

    Perry, C.A.; Daigle, G.A.; Rountree, S.P.; Talmadge, G.; Grunbeck, J.; Wassell, M

    1998-01-01

    An apparatus for nuclear logging is presented. In accordance with the present invention, nuclear detectors and electronic components are all mounted in chambers within the sub wall with covers being removably attached to the chambers. A single bus for delivering both power and signals extends through the sub wall between either end of the tool. This bus terminates at a modular ring connector positioned on each tool end. This tool construction (including sub wall mounted sensors and electronics, single power and signal bus, and ring connectors) is also well suited for other formation evaluation tools used in measurement-while-drilling applications. 28 refs

  20. Nuclear Tools For Oilfield Logging-While-Drilling Applications

    International Nuclear Information System (INIS)

    Reijonen, Jani

    2011-01-01

    Schlumberger is an international oilfield service company with nearly 80,000 employees of 140 nationalities, operating globally in 80 countries. As a market leader in oilfield services, Schlumberger has developed a suite of technologies to assess the downhole environment, including, among others, electromagnetic, seismic, chemical, and nuclear measurements. In the past 10 years there has been a radical shift in the oilfield service industry from traditional wireline measurements to logging-while-drilling (LWD) analysis. For LWD measurements, the analysis is performed and the instruments are operated while the borehole is being drilled. The high temperature, high shock, and extreme vibration environment of LWD imposes stringent requirements for the devices used in these applications. This has a significant impact on the design of the components and subcomponents of a downhole tool. Another significant change in the past few years for nuclear-based oilwell logging tools is the desire to replace the sealed radioisotope sources with active, electronic ones. These active radiation sources provide great benefits compared to the isotopic sources, ranging from handling and safety to nonproliferation and well contamination issues. The challenge is to develop electronic generators that have a high degree of reliability for the entire lifetime of a downhole tool. LWD tool testing and operations are highlighted with particular emphasis on electronic radiation sources and nuclear detectors for the downhole environment.

  1. Handbook on nuclear data for borehole logging and mineral analysis

    International Nuclear Information System (INIS)

    1993-01-01

    In nuclear geophysics, an extension of the nuclear data available for reactor and shielding calculations, is required. In general, the problems and the methods of attack are the same, but in nuclear geophysics the environment is earth materials, with virtually all the natural elements in the Periodic Table involved, although not at the same time. In addition, the geometrical configurations encountered in nuclear geophysics are very different from those associated with reactor and shielding design, and they can impose a different demand on the required accuracy of the nuclear data and on the dependence on the calculational approach. Borehole logging is a very good example, since an experimental investigation aimed at varying only one parameter (e.g. moisture content) whilst keeping all the others constant in a geologically complex system that effectively exhibits 'infinite geometry' for neutrons and γ rays is virtually impossible. An increasingly important are of nuclear geophysics is the on-line analysis of natural materials such as coal (e.g. C, H, O, Al, Si, Ca, Fe, Cl, S, N,) the raw materials of the cement industry (S, Na, K, Al, Si, Ca, Fe, Mn, Ti, P, Mg, F, O), and mined ores of Fe, Al, Mn, Cu, Ni, Ag and Au, amongst others. Refs, figs and tabs

  2. Current trends in nuclear borehole logging techniques for elemental analysis

    International Nuclear Information System (INIS)

    1988-06-01

    This report is the result of a consultants' meeting organized by the IAEA and held in Ottawa, Canada, 2-6 November 1987 in order to assess the present technical status of nuclear borehole logging techniques, to find out the well established applications and the development trends. It contains a summary report giving a comprehensive overview of the techniques and applications and a collection of research papers describing work done in industrial institutes. A separate abstract was prepared for each of these 9 papers. Refs, figs and tabs

  3. The current situation and prospect of fundamental research about nuclear logging technology

    International Nuclear Information System (INIS)

    Zhang Feng; Wang Xinguang; Yuan Chao

    2010-01-01

    Nuclear logging technology is one of the important methods to evaluate complex hydrocarbon reservoir in the process of petroleum exploration and development. The fundamental research of nuclear logging is an important step of logging technology innovation. Through analyzing the current situation of the development of nuclear logging technology at home and abroad in recent years, the problems and gaps are pointed out in the field of fundamental research of nuclear logging at home, and the future development of new nuclear logging technologies is concisely analyzed. Therefore, the optimal design and processing are conducted from aspects of ray source, detector, data acquisition and processing method. In addition, the fundamental research of LWD and pulsed neutron logging technology is taken as the main breach. In the fundamental research of nuclear logging technology, innovative thinking should be expressed and the innovation should be achieved in every field of the development of nuclear logging technology. Meanwhile, the logging key lab should be taken as the platform and the latest achievement in the field of nuclear logging technology should be fully utilized. Thus, the level of independent R and D and technology innovation of logging tools will be raised and service for the exploration and development of petroleum and other mineral resources. (authors)

  4. The efficiency of the use of penetration nuclear logging in hydrogeology and engineering geology

    International Nuclear Information System (INIS)

    Ferronsky, V.I.

    1992-01-01

    The latest developments in equipment and techniques for nuclear and combined non-nuclear logging in friable unconsolidated deposits, including marine bottom sediments are described. The effectiveness of these techniques in hydrogeological and engineering geological investigations is discussed. (Author)

  5. Determination of reservoir effective porosity using nuclear magnetic logging data

    International Nuclear Information System (INIS)

    Aksel'rod, S.M.; Danevich, V.I.; Sadykov, D.M.

    1979-01-01

    In connection with the development of nuclear magnetic logging (NML) the possibility has occurred to determine the effective porosity coefficient for rocks directly under the conditions of their occurrence. The initial amplitude of a signal of free precession of NML is proportional to the quantity of free fluid in the rock volume, which is determined by the index of free fluid (IFF). On the basis of the laboratory studies it is shown that the relation between IFF and free water content is always linear and doesn't depend on lithological characteristics of rocks, porous dimensions and distribution. Using this relation it's possible to estimate bound water content. While filling the reservoir with weakly mineralized water the IFF value coincides numerically with the effective porosity coefficient. Otherwise the content of hydrogen nuclei in a volume unit is much less; while calculating the effective porosity coefficient this fact is recorded by the index of the amplitude decrease which depends on temperature and increases with its growth (for oils). In strata containing intercalations of reservoirs and non-reservoirs the averaged according to stratum IFF value determines the mean-weighted values of effective porosity

  6. Application of computer mathematical modeling in nuclear well-logging industry

    International Nuclear Information System (INIS)

    Cai Shaohui

    1994-01-01

    Nuclear well logging techniques have made rapid progress since the first well log calibration facility (the API pits) was dedicated in 1959. Then came the first computer mathematical model in the late 70's. Mathematical modeling can now minimize design and experiment time, as well as provide new information and idea on tool design, environmental effects and result interpretation. The author gives a brief review on the achievements of mathematical modeling on nuclear logging problems

  7. Nuclear cross section library for oil well logging analysis

    International Nuclear Information System (INIS)

    Kodeli, I.; Kitsos, S.; Aldama, D.L.; Zefran, B.

    2003-01-01

    As part of the IRTMBA (Improved Radiation Transport Modelling for Borehole Applications) Project of the EU Community's 5 th Programme a special purpose multigroup cross section library to be used in the deterministic (as well as Monte Carlo) oil well logging particle transport calculations was prepared. This library is expected to improve the prediction of the neutron and gamma spectra at the detector positions of the logging tool, and their use for the interpretation of the neutron logging measurements was studied. Preparation and testing of this library is described. (author)

  8. Correlating hydrogeostratification with geostratification from nuclear logging and geoelectric sounding in water impregnated traps

    International Nuclear Information System (INIS)

    Bardhan, M.

    1977-01-01

    Subsurface boundary conditions obtained through nuclear logging and geoelectric sounding were compared with the driller's log recorded in a number of boreholes drilled by employing modern down-the-hole hammer rig, to diagnose the relative merits of the methods and to portray the actual subsurface stratigraphic succession as well as hydrophysical conditions in saturated trap formations. It was observed that nuclear logging and resistivity sounding do not furnish the actual geostratigraphy due to lack of sufficient contrast in the relevant physical properties between successive lava flows, but reflects on the prevailing hydrostratigraphy. However, the informations thrown up by them are of immense technical value in guiding ground water development programme through sinking of wells in trappean terrians. It is shown that the horizontal correlation value of nuclear logging can be augmented by combining it with geoelectric sounding. This aids in enhancing the practical utility of nuclear logs in geohydrologic investigations. (author)

  9. Dose estimative in operators during petroleum wells logging with nuclear wireless probes through computer modelling

    International Nuclear Information System (INIS)

    Souza, Edmilson Monteiro de; Silva, Ademir Xavier da; Lopes, Ricardo T.; Correa, Samanda Cristine Arruda; Rocha, Paula L.F.

    2011-01-01

    This paper evaluates the absorbed dose and the effective dose on operators during the petroleum well logging with nuclear wireless that uses gamma radiation sources. To obtain the data, a typical scenery of a logging procedure will be simulated with MCNPX Monte Carlo code. The simulated logging probe was the Density Gamma Probe - TRISOND produced by Robertson Geolloging. The absorbed dose values were estimated through the anthropomorphic simulator in male voxel MAX. The effective dose values were obtained using the ICRP 103

  10. Implementation of variance-reduction techniques for Monte Carlo nuclear logging calculations with neutron sources

    NARCIS (Netherlands)

    Maucec, M

    2005-01-01

    Monte Carlo simulations for nuclear logging applications are considered to be highly demanding transport problems. In this paper, the implementation of weight-window variance reduction schemes in a 'manual' fashion to improve the efficiency of calculations for a neutron logging tool is presented.

  11. Quantitative interpretation of nuclear logging data by adopting point-by-point spectrum striping deconvolution technology

    International Nuclear Information System (INIS)

    Tang Bin; Liu Ling; Zhou Shumin; Zhou Rongsheng

    2006-01-01

    The paper discusses the gamma-ray spectrum interpretation technology on nuclear logging. The principles of familiar quantitative interpretation methods, including the average content method and the traditional spectrum striping method, are introduced, and their limitation of determining the contents of radioactive elements on unsaturated ledges (where radioactive elements distribute unevenly) is presented. On the basis of the intensity gamma-logging quantitative interpretation technology by using the deconvolution method, a new quantitative interpretation method of separating radioactive elements is presented for interpreting the gamma spectrum logging. This is a point-by-point spectrum striping deconvolution technology which can give the logging data a quantitative interpretation. (authors)

  12. Analysis of logging data from nuclear borehole tools

    International Nuclear Information System (INIS)

    Hovgaard, J.; Oelgaard, P.L.

    1989-12-01

    The processing procedure for logging data from a borehole of the Stenlille project of Dansk Naturgas A/S has been analysed. The tools considered in the analysis were an integral, natural-gamma tool, a neutron porosity tool, a gamma density tool and a caliper tool. It is believed that in most cases the processing procedure used by the logging company in the interpretation of the raw data is fully understood. An exception is the epithermal part of the neutron porosity tool where all data needed for an interpretation were not available. The analysis has shown that some parts of the interpretation procedure may not be consistent with the physical principle of the tools. (author)

  13. FLOZ-the computer program for the primary interpretation of nuclear borehole logging

    International Nuclear Information System (INIS)

    Zorski, T.

    1979-01-01

    This work presents the FLOZ program for nuclear well logging data interpretation. Program has been written in FORTRAN 1900 language for ODRA 1300 computers. The description of the program possibilities and the ways of its application are given. Short presentation of the interpretation method used here and the description of the program work with its complete listing, together with the explanatory commentaries are also presented. The type of interpretation performed by the program depends upon the kind of nuclear logging of interest. For neutron-gamma and gamma-gamma logging the program introduces the corrections for the following disturbing factors: the ratemeter time constant, the logging speed, the apparatus dead time, the gamma-ray background. The gamma-ray logging is corrected for the following disturbing factors: ratemeter time constant, the logging speed, the apparatus dead time of tool, borehole radius, gamma-ray absorbtion in the borehole liquid and the finite thickness of the layers. The calibration constant for gamma-ray probe can be introduced for calculations of radioactivity ore grades. The log deflections being the input data for the FLOZ program, are taken from specially prepared magnetic tape. The results of interpretation are written on magnetic tape, according to the X3GY system for the ODRA 1300 computers. The method of interpretation which is applicated in program FLOZ was elaborated by Prof. J.A. Czubek from Institute of Nuclear Physics in Cracow. (author)

  14. Progress in nuclear well logging modeling using deterministic transport codes

    International Nuclear Information System (INIS)

    Kodeli, I.; Aldama, D.L.; Maucec, M.; Trkov, A.

    2002-01-01

    Further studies in continuation of the work presented in 2001 in Portoroz were performed in order to study and improve the performances, precission and domain of application of the deterministic transport codes with respect to the oil well logging analysis. These codes are in particular expected to complement the Monte Carlo solutions, since they can provide a detailed particle flux distribution in the whole geometry in a very reasonable CPU time. Real-time calculation can be envisaged. The performances of deterministic transport methods were compared to those of the Monte Carlo method. IRTMBA generic benchmark was analysed using the codes MCNP-4C and DORT/TORT. Centric as well as excentric casings were considered using 14 MeV point neutron source and NaI scintillation detectors. Neutron and gamma spectra were compared at two detector positions.(author)

  15. Calculation of Monte Carlo importance functions for use in nuclear-well logging calculations

    International Nuclear Information System (INIS)

    Soran, P.D.; McKeon, D.C.; Booth, T.E.

    1989-07-01

    Importance sampling is essential to the timely solution of Monte Carlo nuclear-logging computer simulations. Achieving minimum variance (maximum precision) of a response in minimum computation time is one criteria for the choice of an importance function. Various methods for calculating importance functions will be presented, new methods investigated, and comparisons with porosity and density tools will be shown. 5 refs., 1 tab

  16. Implementation of a tree algorithm in MCNP code for nuclear well logging applications

    Energy Technology Data Exchange (ETDEWEB)

    Li Fusheng, E-mail: fusheng.li@bakerhughes.com [Baker Hughes Incorporated, 2001 Rankin Rd. Houston, TX 77073-5101 (United States); Han Xiaogang [Baker Hughes Incorporated, 2001 Rankin Rd. Houston, TX 77073-5101 (United States)

    2012-07-15

    The goal of this paper is to develop some modeling capabilities that are missing in the current MCNP code. Those missing capabilities can greatly help for some certain nuclear tools designs, such as a nuclear lithology/mineralogy spectroscopy tool. The new capabilities to be developed in this paper include the following: zone tally, neutron interaction tally, gamma rays index tally and enhanced pulse-height tally. The patched MCNP code also can be used to compute neutron slowing-down length and thermal neutron diffusion length. - Highlights: Black-Right-Pointing-Pointer Tree structure programming is suitable for Monte-Carlo based particle tracking. Black-Right-Pointing-Pointer Enhanced pulse height tally is developed for oilwell logging tool simulation. Black-Right-Pointing-Pointer Neutron interaction tally and gamma ray index tally for geochemical logging.

  17. Basalt characterization by means of nuclear and electrical well logging techniques. Case study from Southern Syria

    International Nuclear Information System (INIS)

    Asfahani, Jamal

    2011-01-01

    Nuclear well logging, including natural gamma ray, density, and neutron-porosity techniques are used with electrical well logging of long and short normal techniques to characterize the basaltic areas largely extended in Southern Syria. Statistical analysis approach with the threshold concept has been adapted for such characterization, where four kinds of basalt have been identified: very hard basalt, hard basalt, fractured basalt, and basalt alteration products. The spectrometric gamma technique has also been applied on the retrieved rock samples in order to determine the radioactive content (eU, eTh, and K%) of the basaltic section in the study area. No radioactive anomalies have been detected, the radioactive values are normal and in the expected range.

  18. Problems of the processing of nuclear magnetic logging signals (identification of fluid-containing strata from a number of measurements)

    International Nuclear Information System (INIS)

    Aliev, T.M.; Orlov, G.L.; Lof, V.M.; Mityushin, E.M.; Ragimova, E.K.

    1978-01-01

    Problems of the processing of nuclear magnetic logging signals to identification of fluid-containing strata from a number of measurements. Problems of application statistical decision theory to discovery of fluid-containing beds from a number of measurements are considered. Using the technique possibilities of nuclear magnetic logging method the necessary volume of samples is motivated, the rational algorithm for processing of sequential measurements is obtained

  19. Evaluation of Non-Nuclear Techniques for Well Logging: Technology Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Leonard J.; Denslow, Kayte M.; Griffin, Jeffrey W.; Dale, Gregory E.; Harris, Robert V.; Moran, Traci L.; Sheen, David M.; Schenkel, Thomas

    2010-11-01

    This report presents an initial review of the state-of-the-art nuclear and non-nuclear well logging methods and seeks to understand the technical and economic issues if AmBe, and potentially other isotope sources, are reduced or even eliminated in the oil-field services industry. Prior to considering alternative logging technologies, there is a definite need to open up discussions with industry regarding the feasibility and acceptability of source replacement. Industry views appear to range from those who see AmBe as vital and irreplaceable to those who believe that, with research and investment, it may be possible to transition to electronic neutron sources and employ combinations of non-nuclear technologies to acquire the desired petro-physical parameters. In one sense, the simple answer to the question as to whether petro-physical parameters can be sensed with technologies other than AmBe is probably "Yes". The challenges come when attention turns to record interpretation. The many decades of existing records form a very valuable proprietary resource, and the interpretation of subtle features contained in these records are of significant value to the oil-gas exploration community to correctly characterize a well. The demonstration of equivalence and correspondence/correlation between established and any new sensing modality, and correlations with historic records is critical to ensuring accurate data interpretation. Establishing the technical basis for such a demonstration represents a significant effort.

  20. Use of critical pathway models and log-normal frequency distributions for siting nuclear facilities

    International Nuclear Information System (INIS)

    Waite, D.A.; Denham, D.H.

    1975-01-01

    The advantages and disadvantages of potential sites for nuclear facilities are evaluated through the use of environmental pathway and log-normal distribution analysis. Environmental considerations of nuclear facility siting are necessarily geared to the identification of media believed to be sifnificant in terms of dose to man or to be potential centres for long-term accumulation of contaminants. To aid in meeting the scope and purpose of this identification, an exposure pathway diagram must be developed. This type of diagram helps to locate pertinent environmental media, points of expected long-term contaminant accumulation, and points of population/contaminant interface for both radioactive and non-radioactive contaminants. Confirmation of facility siting conclusions drawn from pathway considerations must usually be derived from an investigatory environmental surveillance programme. Battelle's experience with environmental surveillance data interpretation using log-normal techniques indicates that this distribution has much to offer in the planning, execution and analysis phases of such a programme. How these basic principles apply to the actual siting of a nuclear facility is demonstrated for a centrifuge-type uranium enrichment facility as an example. A model facility is examined to the extent of available data in terms of potential contaminants and facility general environmental needs. A critical exposure pathway diagram is developed to the point of prescribing the characteristics of an optimum site for such a facility. Possible necessary deviations from climatic constraints are reviewed and reconciled with conclusions drawn from the exposure pathway analysis. Details of log-normal distribution analysis techniques are presented, with examples of environmental surveillance data to illustrate data manipulation techniques and interpretation procedures as they affect the investigatory environmental surveillance programme. Appropriate consideration is given these

  1. Computer-modeling codes to improve exploration nuclear-logging methods. National Uranium Resource Evaluation

    International Nuclear Information System (INIS)

    Wilson, R.D.; Price, R.K.; Kosanke, K.L.

    1983-03-01

    As part of the Department of Energy's National Uranium Resource Evaluation (NURE) project's Technology Development effort, a number of computer codes and accompanying data bases were assembled for use in modeling responses of nuclear borehole logging Sondes. The logging methods include fission neutron, active and passive gamma-ray, and gamma-gamma. These CDC-compatible computer codes and data bases are available on magnetic tape from the DOE Technical Library at its Grand Junction Area Office. Some of the computer codes are standard radiation-transport programs that have been available to the radiation shielding community for several years. Other codes were specifically written to model the response of borehole radiation detectors or are specialized borehole modeling versions of existing Monte Carlo transport programs. Results from several radiation modeling studies are available as two large data bases (neutron and gamma-ray). These data bases are accompanied by appropriate processing programs that permit the user to model a wide range of borehole and formation-parameter combinations for fission-neutron, neutron-, activation and gamma-gamma logs. The first part of this report consists of a brief abstract for each code or data base. The abstract gives the code name and title, short description, auxiliary requirements, typical running time (CDC 6600), and a list of references. The next section gives format specifications and/or directory for the tapes. The final section of the report presents listings for programs used to convert data bases between machine floating-point and EBCDIC

  2. Computer-based system for acquisition of nuclear well log data

    International Nuclear Information System (INIS)

    Meisner, J.E.

    1983-01-01

    There is described a computer-based well logging system, for acquiring nuclear well log data, including gamma ray energy spectrum and neutron population decay rate data, and providing a real-time presentation of the data on an operator's display based on a traversal by a downhole instrument of a prescribed borehole depth interval. The system has a multichannel analyzer including a pulse height analyzer and a memory. After a spectral gamma ray pulse signal coming from a downhole instrument over a logging cable is amplified and conditioned, the pulse height analyzer converts the pulse height into a digital code by peak detection, sample-and-hold action, and analog-to-digital conversion. The digital code defines the address of a memory location or channel, corresponding to a particular gamma ray energy and having a count value to be incremented. The spectrum data is then accessed by the system central processing unit (CPU) for analysis, and routed to the operator's display for presentation as a plot of relative gamma ray emissions activity versus energy level. For acquiring neutron decay rate data, the system has a multichannel scaling unit including a memory and a memory address generator. After a burst of neutrons downhole, thermal and epithermal neutron detector pulses build up and die away. Using the neutron source trigger as an initializing reference, the address generator produces a sequence of memory address codes, each code addressing the memory for a prescribed period of time, so as to define a series of time slots. A detector pulse signal produced during a time slot results in the incrementing of the count value in an address memory location. (author)

  3. Development of self-learning Monte Carlo technique for more efficient modeling of nuclear logging measurements

    International Nuclear Information System (INIS)

    Zazula, J.M.

    1988-01-01

    The self-learning Monte Carlo technique has been implemented to the commonly used general purpose neutron transport code MORSE, in order to enhance sampling of the particle histories that contribute to a detector response. The parameters of all the biasing techniques available in MORSE, i.e. of splitting, Russian roulette, source and collision outgoing energy importance sampling, path length transformation and additional biasing of the source angular distribution are optimized. The learning process is iteratively performed after each batch of particles, by retrieving the data concerning the subset of histories that passed the detector region and energy range in the previous batches. This procedure has been tested on two sample problems in nuclear geophysics, where an unoptimized Monte Carlo calculation is particularly inefficient. The results are encouraging, although the presented method does not directly minimize the variance and the convergence of our algorithm is restricted by the statistics of successful histories from previous random walk. Further applications for modeling of the nuclear logging measurements seem to be promising. 11 refs., 2 figs., 3 tabs. (author)

  4. Basalt identification by interpreting nuclear and electrical well logging measurements using fuzzy technique (case study from southern Syria)

    International Nuclear Information System (INIS)

    Asfahani, J.; Abdul Ghani, B.; Ahmad, Z.

    2015-01-01

    Fuzzy analysis technique is proposed in this research for interpreting the combination of nuclear and electrical well logging data, which include natural gamma ray, density and neutron-porosity, while the electrical well logging include long and short normal. The main objective of this work is to describe, characterize and establish the lithology of the large extended basaltic areas in southern Syria. Kodana well logging measurements have been used and interpreted for testing and applying the proposed technique. The established lithological cross section shows the distribution and the identification of four kinds of basalt, which are hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay. The fuzzy analysis technique is successfully applied on the Kodana well logging data, and can be therefore utilized as a powerful tool for interpreting huge well logging data with higher number of variables required for lithological estimations. - Highlights: • Apply fuzzy analysis technique on the nuclear and electrical well logging data of Kodana well in Southern Syria. • Determine and differentiate between four kinds of basalt. • Establish the lithological section of the studied well.

  5. Porosity and hydraulic conductivity estimation of the basaltic aquifer in Southern Syria by using nuclear and electrical well logging techniques

    Science.gov (United States)

    Asfahani, Jamal

    2017-08-01

    An alternative approach using nuclear neutron-porosity and electrical resistivity well logging of long (64 inch) and short (16 inch) normal techniques is proposed to estimate the porosity and the hydraulic conductivity ( K) of the basaltic aquifers in Southern Syria. This method is applied on the available logs of Kodana well in Southern Syria. It has been found that the obtained K value by applying this technique seems to be reasonable and comparable with the hydraulic conductivity value of 3.09 m/day obtained by the pumping test carried out at Kodana well. The proposed alternative well logging methodology seems as promising and could be practiced in the basaltic environments for the estimation of hydraulic conductivity parameter. However, more detailed researches are still required to make this proposed technique very performed in basaltic environments.

  6. Application of intrinsic germanium spectral gamma-ray logging for characterization of high-level nuclear waste tank leaks

    International Nuclear Information System (INIS)

    Brodeur, J.R.; Kiesler, J.P.; Kos, S.E.; Koizumi, C.J.; Nicaise, W.F.; Price, R.K.

    1993-11-01

    Spectral gamma-ray logging with a high-resolution, intrinsic germanium logging system was completed in boreholes surrounding two high-level nuclear waste tanks at the US Department of Energy's Hanford Site. The purpose was to characterize the concentrations of man-made radionuclides in the unsaturated zone sediments and identify any new leaks from the tanks. An intrinsic germanium detection system was used for this work because it was important to positively identify the specific radionuclides and to precisely assay those radionuclides. The spectral gamma log data were processed and displayed as log plots for each individual borehole and as three-dimensional plots of 137 Cs radionuclide concentrations. These data were reviewed to identify the sources of the contamination. The investigation did not uncover a new or active leak from either of the tanks. Most of the contamination found could be related to known pipeline leaks, to surface contamination from aboveground liquid spills, or to leaks from other tanks. The current spectral gamma ray data now provide a new baseline from which to compare future log data and identify any changes in the radioelement concentration

  7. Nuclear logging apparatus and MWD-equipment for formation evaluation; Nukleart loggeapparat og MWD-verktoey til formasjonsevaluering

    Energy Technology Data Exchange (ETDEWEB)

    Perry, C.A.; Daigle, G.A.; Rountree, S.P.; Talmadge, G.; Grunbeck, J.; Wassell, M

    1998-10-12

    An apparatus for nuclear logging is presented. In accordance with the present invention, nuclear detectors and electronic components are all mounted in chambers within the sub wall with covers being removably attached to the chambers. A single bus for delivering both power and signals extends through the sub wall between either end of the tool. This bus terminates at a modular ring connector positioned on each tool end. This tool construction (including sub wall mounted sensors and electronics, single power and signal bus, and ring connectors) is also well suited for other formation evaluation tools used in measurement-while-drilling applications. 28 refs.

  8. Encyclopedia of well logging

    International Nuclear Information System (INIS)

    Desbrandes, R.

    1985-01-01

    The 16 chapters of this book aim to provide students, trainees and engineers with a manual covering all well-logging measurements ranging from drilling to productions, from oil to minerals going by way of geothermal energy. Each chapter is a summary but a bibliography is given at the end of each chapter. Well-logging during drilling, wireline logging equipment and techniques, petroleum logging, data processing of borehole data, interpretation of well-logging, sampling tools, completion and production logging, logging in relief wells to kill off uncontrolled blowouts, techniques for high temperature geothermal energy, small-scale mining and hydrology, logging with oil-base mud and finally recommended logging programs are all topics covered. There is one chapter on nuclear well-logging which is indexed separately. (UK)

  9. Processing and display of nuclear magnetism logging signals: application to residual oil determination

    International Nuclear Information System (INIS)

    Brown, R.J.S.; Neuman, C.H.

    1980-01-01

    A presentation is made of a series of computations and signal displays which help to show the nature of NML signals in general as well as to show the response to particular formation, hole, and tool conditions. Such processing of digitally recorded signals enables improved accuracy and bed resolution over that presented with the raw log. The treatment of drilling mud filtrate to eliminate NML signal from the brine phase in the invaded zone is described. Logs are shown as recorded before and after invasion of treated mud filtrate. This treatment causes the NML signal to correspond to residual oil only, enabling accurate and relatively inexpensive measurement of residual oil. 24 refs

  10. An approach to derive some simple empirical equations to calibrate nuclear and acoustic well logging tools.

    Science.gov (United States)

    Mohammad Al Alfy, Ibrahim

    2018-01-01

    A set of three pads was constructed from primary materials (sand, gravel and cement) to calibrate the gamma-gamma density tool. A simple equation was devised to convert the qualitative cps values to quantitative g/cc values. The neutron-neutron porosity tool measures the qualitative cps porosity values. A direct equation was derived to calculate the porosity percentage from the cps porosity values. Cement-bond log illustrates the cement quantities, which surround well pipes. This log needs a difficult process due to the existence of various parameters, such as: drilling well diameter as well as internal diameter, thickness and type of well pipes. An equation was invented to calculate the cement percentage at standard conditions. This equation can be modified according to varying conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Estimating the whole-body exposure annual dose of radiation workers of petroleum nuclear well logging

    International Nuclear Information System (INIS)

    Tian Yizong; Gao Jianzheng; Liu Wenhong

    2006-01-01

    Objective: By imitating experiment of radioactive sources being installed, to estimate the annual whole-body exposure dose of radiation workers of petroleum nuclear determining wells; Methods: To compre the values of the theory, imitating experiment and γ individual dose monitor calculations. Results: The three values measured above tally with one anather. Conclusion: The annual whole-body exposure doses of radiation workers of petroleum nuclear determining wells are no more than 5 mSv. (authors)

  12. Implementation of a tree algorithm in MCNP code for nuclear well logging applications.

    Science.gov (United States)

    Li, Fusheng; Han, Xiaogang

    2012-07-01

    The goal of this paper is to develop some modeling capabilities that are missing in the current MCNP code. Those missing capabilities can greatly help for some certain nuclear tools designs, such as a nuclear lithology/mineralogy spectroscopy tool. The new capabilities to be developed in this paper include the following: zone tally, neutron interaction tally, gamma rays index tally and enhanced pulse-height tally. The patched MCNP code also can be used to compute neutron slowing-down length and thermal neutron diffusion length. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Dose estimative in operators during petroleum wells logging with nuclear wireless probes through computer modelling; Estimativa da dose em operadores durante procedimentos de perfilagem de pocos de petroleo com sondas wireless nucleares atraves de modelagem computacional

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Edmilson Monteiro de; Silva, Ademir Xavier da; Lopes, Ricardo T., E-mail: emonteiro@nuclear.ufrj.b, E-mail: ademir@nuclear.ufrj.b, E-mail: ricardo@lin.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Lima, Inaya C.B., E-mail: inaya@lin.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Instituto Politecnico do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil); Correa, Samanda Cristine Arruda, E-mail: scorrea@cnen.gov.b [Comissao Nacional de Energia Nuclear (DIAPI/CGMI/CNEN), Rio de Janeiro, RJ (Brazil); Rocha, Paula L.F., E-mail: ferrucio@acd.ufrj.b [Universidade Federal do Rio de Janeiro (UFRJ)., RJ (Brazil). Dept. de Geologia

    2011-10-26

    This paper evaluates the absorbed dose and the effective dose on operators during the petroleum well logging with nuclear wireless that uses gamma radiation sources. To obtain the data, a typical scenery of a logging procedure will be simulated with MCNPX Monte Carlo code. The simulated logging probe was the Density Gamma Probe - TRISOND produced by Robertson Geolloging. The absorbed dose values were estimated through the anthropomorphic simulator in male voxel MAX. The effective dose values were obtained using the ICRP 103

  14. Borehole logging

    International Nuclear Information System (INIS)

    Olsen, H.

    1995-01-01

    Numerous ground water investigations have been accomplished by means of borehole logging. Borehole logging can be applied to establish new water recovery wells, to control the existing water producing wells and source areas and to estimate ground water quality. (EG)

  15. Use of borehole-geophysical logs and hydrologic tests to characterize crystalline rock for nuclear-waste storage, Whiteshell Nuclear Research Establishment, Manitoba, and Chalk River Nuclear Laboratory, Ontario, Canada

    International Nuclear Information System (INIS)

    Davison, C.C.

    1982-12-01

    A number of borehole methods were used in the investigation of crystalline rocks at Whiteshell Nuclear Research Establishment and Chalk River Nuclear Laboratory in Canada. The selection of a crystalline-rock mass for the storage of nuclear waste likely will require the drilling and testing of a number of deep investigative boreholes in the rock mass. Although coring of at least one hole in each new area is essential, methods for making in-situ geophysical and hydrologic measurements can substitute for widespread coring and result in significant savings in time and money. Borehole-geophysical logging techniques permit the lateral extrapolation of data from a core hole. Log response is related to rock type, alteration, and the location and character of fractures. The geophysical logs that particularly are useful for these purposes are the acoustic televiewer and acoustic waveform, neutron and gamma, resistivity, temperature, and caliper. The acoustic-televiewer log of the borehole wall can provide high resolution data on the orientation and apparent width of fractures. In situ hydraulic tests of single fractures or fracture zones isolated by packers provide quantitative information on permeability, extent, and interconnection. The computer analysis of digitized acoustic waveforms has identified a part of the waveform that has amplitude variations related to permeabilities measured in the boreholes by packer tests. 38 refs., 37 figs., 4 tabs

  16. The use of borehole geophysical logs and hydrologic tests to characterize plutonic rock for nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Davison, C.C.

    1984-05-01

    The selection of an igneous rock body for the disposal of nuclear fuel waste will likely require the drilling and testing of a number of deep investigative boreholes in the rock body. Although coring of at least one hole at each Research Area will be essential, methods for making in situ geophysical and hydrological measurements can substitute for widespread coring and result in significant savings in time and money. A number of borehole methods have been applied to the investigation of plutonic rocks at Whiteshell Nuclear Research Establishment and Chalk River Nuclear Laboratories in Canada

  17. Vadose zone monitoring plan using geophysical nuclear logging for radionuclides discharged to Hanford liquid waste disposal facilities

    International Nuclear Information System (INIS)

    Price, R.K.

    1995-11-01

    During plutonium production at Hanford, large quantities of hazardous and radioactive liquid effluent waste have been discharged to the subsurface (vadose zone). These discharges at over 330 liquid effluent disposal facilities (ie. cribs, ditches, and ponds) account for over 3,000,000 curies of radioactive waste released into the subsurface. It is estimated that 10% of the contaminants have reached the groundwater in many places. Continuing migration may further impact groundwater quality in the future. Through the RCRA Operational Monitoring Program, a Radionuclide Logging System (RLS) has been obtained by Hanford Technical Services (HTS) and enhanced to measure the distribution of contaminants and monitor radionuclide movement in existing groundwater and vadose zone boreholes. Approximately 100 wells are logged by HTS each year in this program. In some cases, movement has been observed years after discharges were terminated. A similar program is in place to monitor the vadose zone at the Tank Farms. This monitoring plan describes Hanford Programs for monitoring the movement of radioactive contamination in the vadose zone. Program background, drivers, and strategy are presented. The objective of this program is to ensure that DOE-RL is aware of any migration of contaminants in the vadose zone, such that groundwater can be protected and early actions can be taken as needed

  18. Engineering aspects of radiometric logging

    International Nuclear Information System (INIS)

    Huppert, P.

    1982-01-01

    Engineering problems encountered in the development of nuclear borehole logging techniques are discussed. Spectrometric techniques require electronic stability of the equipment. In addition the electronics must be capable of handling high count rates of randomly distributed pulses of fast rise time from the detector and the systems must be designed so that precise calibration is possible under field operating conditions. Components of a logging system are discussed in detail. They include the logging probe (electronics, detector, high voltage supply, preamplifier), electronic instrumentation for data collection and processing and auxiliary equipment

  19. Geophysical borehole logging

    International Nuclear Information System (INIS)

    McCann, D.; Barton, K.J.; Hearn, K.

    1981-08-01

    Most of the available literature on geophysical borehole logging refers to studies carried out in sedimentary rocks. It is only in recent years that any great interest has been shown in geophysical logging in boreholes in metamorphic and igneous rocks following the development of research programmes associated with geothermal energy and nuclear waste disposal. This report is concerned with the programme of geophysical logging carried out on the three deep boreholes at Altnabreac, Caithness, to examine the effectiveness of these methods in crystalline rock. Of particular importance is the assessment of the performance of the various geophysical sondes run in the boreholes in relation to the rock mass properties. The geophysical data can be used to provide additional in-situ information on the geological, hydrogeological and engineering properties of the rock mass. Fracturing and weathering in the rock mass have a considerable effect on both the design parameters for an engineering structure and the flow of water through the rock mass; hence, the relation between the geophysical properties and the degree of fracturing and weathering is examined in some detail. (author)

  20. Method and apparatus for nuclear logging making use of lithium detectors and equipment for gamma ray stripping; Fremgangsmaate og apparat til nuklear logging med bruk av litiummontasjer og anordning for gammastraalestripping

    Energy Technology Data Exchange (ETDEWEB)

    Perry, C.A.; Daigle, G.A.; Bruck, W.D. [and others

    1998-05-11

    The patent deals with a borehole logging tool where a pair of spaced-apart lithium detectors is lowered into a borehole traversing a sursurface formation. The formation is irradiated with bursts of neutrons, and the neutrons returning to the borehole are detected by thermal neutron detectors. The dieaway gamma ray spectra provide information on the formation porosity. A MWD system includes a programmable gain amplifier and gamma ray stripping means. 30 figs.

  1. Specific features of well logging of boreholes drilled on electrical nonconducting solutions

    International Nuclear Information System (INIS)

    Ruchkin, A.F.; Fomenko, V.G.

    1978-01-01

    Methods for identification of permeable strata and determination of their porosity and oil-gas saturation using standard combination of geophysical investigations in the boreholes drilled with nonaqueous and inert drilling fluids are considered. Geophysical combination consists of the methods indications of which are independent on electrical conductivity of drilling fluids. They are all modifications of radioactivity logging (gamma logging, neutron logging, neutron-gamma logging, gamma-gamma logging, pulsed neutron logging, nuclear-magnetic logging), acoustic logging and thermal logging

  2. Development of a simple proton nuclear magnetic resonance-based procedure to estimate the approximate distribution coefficient at physiological pH (logD7.4)

    DEFF Research Database (Denmark)

    Stéen, E Johanna L; Nyberg, Nils; Lehel, Szabolcs

    2017-01-01

    D7.4) in 1-octanol and D2O buffer. The method can be applied to both UV and non-UV active compounds. In addition, neither calibration curves nor internal/external standards are needed. We have demonstrated that logD7.4 can be accurately measured using 1H NMR for compounds within the logD7.4 interval...

  3. http Log Analysis

    DEFF Research Database (Denmark)

    Bøving, Kristian Billeskov; Simonsen, Jesper

    2004-01-01

    This article documents how log analysis can inform qualitative studies concerning the usage of web-based information systems (WIS). No prior research has used http log files as data to study collaboration between multiple users in organisational settings. We investigate how to perform http log...... analysis; what http log analysis says about the nature of collaborative WIS use; and how results from http log analysis may support other data collection methods such as surveys, interviews, and observation. The analysis of log files initially lends itself to research designs, which serve to test...... hypotheses using a quantitative methodology. We show that http log analysis can also be valuable in qualitative research such as case studies. The results from http log analysis can be triangulated with other data sources and for example serve as a means of supporting the interpretation of interview data...

  4. Log N-log S in inconclusive

    Science.gov (United States)

    Klebesadel, R. W.; Fenimore, E. E.; Laros, J.

    1983-01-01

    The log N-log S data acquired by the Pioneer Venus Orbiter Gamma Burst Detector (PVO) are presented and compared to similar data from the Soviet KONUS experiment. Although the PVO data are consistent with and suggestive of a -3/2 power law distribution, the results are not adequate at this state of observations to differentiate between a -3/2 and a -1 power law slope.

  5. The Meaning of Logs

    NARCIS (Netherlands)

    Etalle, Sandro; Massacci, Fabio; Yautsiukhin, Artsiom

    2007-01-01

    While logging events is becoming increasingly common in computing, in communication and in collaborative work, log systems need to satisfy increasingly challenging (if not conflicting) requirements.Despite the growing pervasiveness of log systems, to date there is no high-level framework which

  6. The Meaning of Logs

    NARCIS (Netherlands)

    Etalle, Sandro; Massacci, Fabio; Yautsiukhin, Artsiom; Lambrinoudakis, Costas; Pernul, Günther; Tjoa, A Min

    While logging events is becoming increasingly common in computing, in communication and in collaborative environments, log systems need to satisfy increasingly challenging (if not conflicting) requirements. In this paper we propose a high-level framework for modeling log systems, and reasoning about

  7. LogScope

    Science.gov (United States)

    Havelund, Klaus; Smith, Margaret H.; Barringer, Howard; Groce, Alex

    2012-01-01

    LogScope is a software package for analyzing log files. The intended use is for offline post-processing of such logs, after the execution of the system under test. LogScope can, however, in principle, also be used to monitor systems online during their execution. Logs are checked against requirements formulated as monitors expressed in a rule-based specification language. This language has similarities to a state machine language, but is more expressive, for example, in its handling of data parameters. The specification language is user friendly, simple, and yet expressive enough for many practical scenarios. The LogScope software was initially developed to specifically assist in testing JPL s Mars Science Laboratory (MSL) flight software, but it is very generic in nature and can be applied to any application that produces some form of logging information (which almost any software does).

  8. Radiometric well logging instruments

    International Nuclear Information System (INIS)

    Davydov, A.V.

    1975-01-01

    The technical properties of well instruments for radioactive logging used in the radiometric logging complexes PKS-1000-1 (''Sond-1'') and PRKS-2 (''Vitok-2'') are described. The main features of the electric circuit of the measuring channels are given

  9. Power to the logs!

    CERN Multimedia

    CERN. Geneva; MACMAHON, Joseph

    2015-01-01

    Are you tired of using grep, vi and emacs to read your logs? Do you feel like you’re missing the big picture? Does the word "statistics" put a smile on your face? Then it’s time to give power to the logs!

  10. Digital mineral logging system

    International Nuclear Information System (INIS)

    West, J.B.

    1980-01-01

    A digital mineral logging system acquires data from a mineral logging tool passing through a borehole and transmits the data uphole to an electronic digital signal processor. A predetermined combination of sensors, including a deviometer, is located in a logging tool for the acquisition of the desired data as the logging tool is raised from the borehole. Sensor data in analog format is converted in the logging tool to a digital format and periodically batch transmitted to the surface at a predetermined sampling rate. An identification code is provided for each mineral logging tool, and the code is transmitted to the surface along with the sensor data. The self-identifying tool code is transmitted to the digital signal processor to identify the code against a stored list of the range of numbers assigned to that type of tool. The data is transmitted up the d-c power lines of the tool by a frequency shift key transmission technique. At the surface, a frequency shift key demodulation unit transmits the decoupled data to an asynchronous receiver interfaced to the electronic digital signal processor. During a recording phase, the signals from the logging tool are read by the electronic digital signal processor and stored for later processing. During a calculating phase, the stored data is processed by the digital signal processor and the results are outputted to a printer or plotter, or both

  11. Feasibility studies of a carbon/oxygen logging tool for evaluating the CO2 content of the medium in nuclear device containment

    International Nuclear Information System (INIS)

    West, H.I. Jr.; Glasgow, J.E.

    1983-12-01

    The feasibility of using oil-well bore-hole logging techniques for assaying the carbonate content of a potential shot site has been investigated. The procedure makes use of the detection of the 4439-keV γ ray of carbon and the 6130-keV γ ray of oxygen produced by the inelastic scattering of 14-MeV neutrons in the bore-hole medium. For the needs of the containment program, a sensitivity of detection of CO 2 to less than or equal to 0.02 weight fraction must be achieved. Laboratory measurements indicate that only with considerable development effort could a tool be made that would come close to achieving this goal

  12. Mariners Weather Log

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Mariners Weather Log (MWL) is a publication containing articles, news and information about marine weather events and phenomena, worldwide environmental impact...

  13. Log-inject-log in sand consolidation

    International Nuclear Information System (INIS)

    Murphy, R.P.; Spurlock, J.W.

    1977-01-01

    A method is described for gathering information for the determination of the adequacy of placement of sand consolidating plastic for sand control in oil and gas wells. The method uses a high neutron cross-section tracer which becomes part of the plastic and uses pulsed neutron logging before and after injection of the plastic. Preferably, the method uses lithium, boron, indium, and/or cadmium tracers. Boron oxide is especially useful and can be dissolved in alcohol and mixed with the plastic ingredients

  14. Elephant logging and environment

    International Nuclear Information System (INIS)

    Tin-Aung-Hla

    1995-01-01

    The natural environment comprises non-biological elements such as air, water, light, heat and biological elements of animal and plant life; all interact with each other to create an ecosystem. Human activities like over-exploitation of forest results in deforestation and desertification. This consequently changes ecological balance. Topics on: (1) history of elephants utilization; (2) elephant logging; (3) classification of elephants; (4) dragging gear; (5) elephant power; (6) elephant logging and environment, are discussed

  15. Well logging. Acquisition and applications; Diagraphies. Acquisition et applications

    Energy Technology Data Exchange (ETDEWEB)

    Serra, O.; Serra, L.

    2001-07-01

    This reference book on wire-line and LWD well logging covers all geophysical methods of underground survey in a synthetic, visual and dynamical way. It treats of: the physical principle of well logging measurements, the different types of existing probes, the factors that can influence the measurements, and the applications of these measurements. The following well-logging methods are reviewed: resistivity; electromagnetic wave propagation; magnetic susceptibility and magnetic field; spontaneous potential; nuclear logging: natural gamma radioactivity, density logging, photoelectric index, neutron emission probes, hydrogen index or neutron porosity, neutron induced gamma spectroscopy, neutron relaxation time, NMR; acoustic measurements: sonic logging, seismic profiles; texture, structure and stratigraphy data acquisition; borehole diameter measurement; temperature measurement; wire sampling methods; place and role of well-logging in petroleum exploration; well-logging programs. (J.S.)

  16. Log4J

    CERN Document Server

    Perry, Steven

    2009-01-01

    Log4j has been around for a while now, and it seems like so many applications use it. I've used it in my applications for years now, and I'll bet you have too. But every time I need to do something with log4j I've never done before I find myself searching for examples of how to do whatever that is, and I don't usually have much luck. I believe the reason for this is that there is a not a great deal of useful information about log4j, either in print or on the Internet. The information is too simple to be of real-world use, too complicated to be distilled quickly (which is what most developers

  17. Mechanics of log calibration

    International Nuclear Information System (INIS)

    Waller, W.C.; Cram, M.E.; Hall, J.E.

    1975-01-01

    For any measurement to have meaning, it must be related to generally accepted standard units by a valid and specified system of comparison. To calibrate well-logging tools, sensing systems are designed which produce consistent and repeatable indications over the range for which the tool was intended. The basics of calibration theory, procedures, and calibration record presentations are reviewed. Calibrations for induction, electrical, radioactivity, and sonic logging tools will be discussed. The authors' intent is to provide an understanding of the sources of errors, of the way errors are minimized in the calibration process, and of the significance of changes in recorded calibration data

  18. Logging Concessions Enable Illegal Logging Crisis in the Peruvian Amazon

    OpenAIRE

    Finer, Matt; Jenkins, Clinton N.; Sky, Melissa A. Blue; Pine, Justin

    2014-01-01

    The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US?Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3%...

  19. Log of Apollo 11.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    The major events of the first manned moon landing mission, Apollo 11, are presented in chronological order from launch time until arrival of the astronauts aboard the U.S.S. Hornet. The log is descriptive, non-technical, and includes numerous color photographs of the astronauts on the moon. (PR)

  20. Borehole logging system

    International Nuclear Information System (INIS)

    Allen, L.S.

    1988-01-01

    A radioactive borehole logging tool employs an epithermal neutron detector having a neutron counter surrounded by an inner thermal neutron filter and an outer thermal neutron filter. Located between the inner and outer filters is a neutron moderating material for extending the lifetime of epithermal neutrons to enhance the counting rate of such epithermal neutrons by the neutron counter

  1. Neutron--neutron logging

    International Nuclear Information System (INIS)

    Allen, L.S.

    1977-01-01

    A borehole logging tool includes a steady-state source of fast neutrons, two epithermal neutron detectors, and two thermal neutron detectors. A count rate meter is connected to each neutron detector. A first ratio detector provides an indication of the porosity of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two epithermal neutron detectors. A second ratio detector provides an indication of both porosity and macroscopic absorption cross section of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two thermal neutron detectors. By comparing the signals of the two ratio detectors, oil bearing zones and salt water bearing zones within the formation being logged can be distinguished and the amount of oil saturation can be determined. 6 claims, 2 figures

  2. Pulsed radiation decay logging

    International Nuclear Information System (INIS)

    Mills, W.R. Jr.

    1983-01-01

    There are provided new and improved well logging processes and systems wherein the detection of secondary radiation is accomplished during a plurality of time windows in a manner to accurately characterize the decay rate of the secondary radiation. The system comprises a well logging tool having a primary pulsed radiation source which emits repetitive time-spaced bursts of primary radiation and detector means for detecting secondary radiation resulting from the primary radiation and producing output signals in response to the detected radiation. A plurality of measuring channels are provided, each of which produces a count rate function representative of signals received from the detector means during successive time windows occurring between the primary radiation bursts. The logging system further comprises means responsive to the measuring channels for producing a plurality of functions representative of the ratios of the radiation count rates measured during adjacent pairs of the time windows. Comparator means function to compare the ratio functions and select at least one of the ratio functions to generate a signal representative of the decay rate of the secondary radiation

  3. Pulse neutron logging technique

    International Nuclear Information System (INIS)

    Bespalov, D.F.; Dylyuk, A.A.

    1975-01-01

    A new method of neutron-burst logging is proposed, residing in irradiating rocks with fast neutron bursts and registering the integrated flux burst of thermal and/or epithermal neutrons, from the moment of its initiation to that of full absorption. The obtaained value is representative of the rock properties (porosity, hydrogen content). The integrated flux in a burst of thermal and epithermal neutrons can be measured both by way of activation of a reference sample of a known chemical composition during the neutron burst and by recording the radiation of induced activity of the sample within an interval between two bursts. The proposed method features high informative value, accuracy and efficiency

  4. Geophysical borehole logging in the unsaturated zone, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Schimschal, U.; Nelson, P.H.

    1991-01-01

    Borehole geophysical logging for site characterization in the volcanic rocks at the proposed nuclear waste repository at Yucca Mountain, Nevada, requires data collection under rather unusual conditions. Logging tools must operate in rugose, dry holes above the water table in the unsaturated zone. Not all logging tools will operate in this environment, therefore; careful consideration must be given to selection and calibration. A sample suite of logs is presented that demonstrates correlation of geological formations from borehole to borehole, the definition of zones of altered mineralogy, and the quantitative estimates of rock properties. The authors show the results of an exploratory calculation of porosity and water saturation based upon density and epithermal neutron logs. Comparison of the results with a few core samples is encouraging, particularly because the logs can provide continuous data in boreholes where core samples are not available

  5. Nova Event Logging System

    International Nuclear Information System (INIS)

    Calliger, R.J.; Suski, G.J.

    1981-01-01

    Nova is a 200 terawatt, 10-beam High Energy Glass Laser currently under construction at LLNL. This facility, designed to demonstrate the feasibility of laser driven inertial confinement fusion, contains over 5000 elements requiring coordinated control, data acquisition, and analysis functions. The large amounts of data that will be generated must be maintained over the life of the facility. Often the most useful but inaccessible data is that related to time dependent events associated with, for example, operator actions or experiment activity. We have developed an Event Logging System to synchronously record, maintain, and analyze, in part, this data. We see the system as being particularly useful to the physics and engineering staffs of medium and large facilities in that it is entirely separate from experimental apparatus and control devices. The design criteria, implementation, use, and benefits of such a system will be discussed

  6. Querying Workflow Logs

    Directory of Open Access Journals (Sweden)

    Yan Tang

    2018-01-01

    Full Text Available A business process or workflow is an assembly of tasks that accomplishes a business goal. Business process management is the study of the design, configuration/implementation, enactment and monitoring, analysis, and re-design of workflows. The traditional methodology for the re-design and improvement of workflows relies on the well-known sequence of extract, transform, and load (ETL, data/process warehousing, and online analytical processing (OLAP tools. In this paper, we study the ad hoc queryiny of process enactments for (data-centric business processes, bypassing the traditional methodology for more flexibility in querying. We develop an algebraic query language based on “incident patterns” with four operators inspired from Business Process Model and Notation (BPMN representation, allowing the user to formulate ad hoc queries directly over workflow logs. A formal semantics of this query language, a preliminary query evaluation algorithm, and a group of elementary properties of the operators are provided.

  7. Interpretation of horizontal well production logs: influence of logging tool

    Energy Technology Data Exchange (ETDEWEB)

    Ozkan, E. [Colorado School of Mines, Boulder, CO (United States); Sarica, C. [Pennsylvania State Univ., College Park, PA (United States); Haci, M. [Drilling Measurements, Inc (United States)

    1998-12-31

    The influence of a production-logging tool on wellbore flow rate and pressure measurements was investigated, focusing on the disturbence caused by the production-logging tool and the coiled tubing on the original flow conditions in the wellbore. The investigation was carried out using an analytical model and single-phase liquid flow was assumed. Results showed that the production-logging tool influenced the measurements as shown by the deviation of the original flow-rate, pressure profiles and low-conductivity wellbores. High production rates increase the effect of the production-logging tool. Recovering or inferring the original flow conditions in the wellbore from the production-logging data is a very complex process which cannot be solved easily. For this reason, the conditions under which the information obtained by production-logging is meaningful is of considerable practical interest. 7 refs., 2 tabs., 15 figs.

  8. Detection of defects in logs using computer assisted tomography (CAT) scanning

    International Nuclear Information System (INIS)

    Tonner, P.D.; Lupton, L.R.

    1985-01-01

    The Chalk River Nuclear Laboratories of AECL have performed a preliminary feasibility study on the applicability of computer assisted tomographic techniques to detect the internal structure of logs. Cross sections of three logs have been obtained using a medical CAT scanner. The results show that knots, rot and growth rings are easily recognized in both dry and wet logs

  9. Logging Concessions Enable Illegal Logging Crisis in the Peruvian Amazon

    Science.gov (United States)

    Finer, Matt; Jenkins, Clinton N.; Sky, Melissa A. Blue; Pine, Justin

    2014-04-01

    The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms.

  10. Logging concessions enable illegal logging crisis in the Peruvian Amazon.

    Science.gov (United States)

    Finer, Matt; Jenkins, Clinton N; Sky, Melissa A Blue; Pine, Justin

    2014-04-17

    The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms.

  11. Cased-hole log analysis and reservoir performance monitoring

    CERN Document Server

    Bateman, Richard M

    2015-01-01

    This book addresses vital issues, such as the evaluation of shale gas reservoirs and their production. Topics include the cased-hole logging environment, reservoir fluid properties; flow regimes; temperature, noise, cement bond, and pulsed neutron logging; and casing inspection. Production logging charts and tables are included in the appendices. The work serves as a comprehensive reference for production engineers with upstream E&P companies, well logging service company employees, university students, and petroleum industry training professionals. This book also: ·       Provides methods of conveying production logging tools along horizontal well segments as well as measurements of formation electrical resistivity through casing ·       Covers new information on fluid flow characteristics in inclined pipe and provides new and improved nuclear tool measurements in cased wells ·       Includes updates on cased-hole wireline formation testing  

  12. Well logging system with linearity control

    International Nuclear Information System (INIS)

    Jones, J.M.

    1973-01-01

    Apparatus is described for controlling the gain of a nuclear well logging system comprising: (1) means for measuring the energy spectrum of gamma rays produced by earth formation materials surrounding a well borehole; (2) means for measuring the number of counts of a gamma rays having an energy falling within each of at least two predetermined energy band portions of the gamma ray energy spectrum; (3) means for generating a signal proportional to the ratio of the gamma ray counts and for comparing the ratio signal with at least one constant ratio calibration signal; (4) means for generating an error signal representative of the difference of the ratio signal and the constant ratio calibration signal; and (5) means for using the error signal to control the linearity of the well logging system. (author)

  13. SNG-logs at Skjern

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Petersen, Jesper; Aage, Helle Karina

    1998-01-01

    Spectral Natural Gamma-ray logs have been run in two water supply borings at Skjern. The log data have been examined by a new technique - Noise Adjusted Singular Value Decomposition - in order to get a detailed and reliable picture of the distribution of uranium and thorium gamma-rays from heavy...

  14. Long term corrosion of iron at the water logged site Nydam in Denmark

    DEFF Research Database (Denmark)

    Matthiesen, Henning; Hilbert, Lisbeth Rischel; Gregory, David

    2005-01-01

    Long term corrosion of iron at the water logged site Nydam in Denmark; studies of enviroment, archaeological artefacts, and modern analogues, Prediction of long term corrosion behaviour in nuclear waste systems.......Long term corrosion of iron at the water logged site Nydam in Denmark; studies of enviroment, archaeological artefacts, and modern analogues, Prediction of long term corrosion behaviour in nuclear waste systems....

  15. Log-balanced combinatorial sequences

    Directory of Open Access Journals (Sweden)

    Tomislav Došlic

    2005-01-01

    Full Text Available We consider log-convex sequences that satisfy an additional constraint imposed on their rate of growth. We call such sequences log-balanced. It is shown that all such sequences satisfy a pair of double inequalities. Sufficient conditions for log-balancedness are given for the case when the sequence satisfies a two- (or more- term linear recurrence. It is shown that many combinatorially interesting sequences belong to this class, and, as a consequence, that the above-mentioned double inequalities are valid for all of them.

  16. VT Route Log Points 2017

    Data.gov (United States)

    Vermont Center for Geographic Information — This data layer is used with VTrans' Integrated Route Log System (IRA). It is also used to calibrate the linear referencing systems, including the End-to-End and...

  17. New materials for fireplace logs

    Science.gov (United States)

    Kieselback, D. J.; Smock, A. W.

    1971-01-01

    Fibrous insulation and refractory concrete are used for logs as well as fireproof walls, incinerator bricks, planters, and roof shingles. Insulation is lighter and more shock resistant than fireclay. Lightweight slag bonded with refractory concrete serves as aggregrate.

  18. Palm distributions for log Gaussian Cox processes

    DEFF Research Database (Denmark)

    Coeurjolly, Jean-Francois; Møller, Jesper; Waagepetersen, Rasmus Plenge

    2017-01-01

    This paper establishes a remarkable result regarding Palm distributions for a log Gaussian Cox process: the reduced Palm distribution for a log Gaussian Cox process is itself a log Gaussian Cox process that only differs from the original log Gaussian Cox process in the intensity function. This new...... result is used to study functional summaries for log Gaussian Cox processes....

  19. Log quality enhancement: A systematic assessment of logging company wellsite performance and log quality

    International Nuclear Information System (INIS)

    Farnan, R.A.; Mc Hattie, C.M.

    1984-01-01

    To improve the monitoring of logging company performance, computer programs were developed to assess information en masse from log quality check lists completed on wellsite by the service company engineer and Phillips representative. A study of all logging jobs performed by different service companies for Phillips in Oklahoma (panhandle excepted) during 1982 enabled several pertinent and beneficial interpretations to be made. Company A provided the best tool and crew service. Company B incurred an excessive amount of lost time related to tool failure, in particular the neutron-density tool combination. Company C, although used only three times, incurred no lost time. With a reasonable data base valid conclusions were made pertaining, for example, to repeated tool malfunctions. The actual logs were then assessed for quality

  20. Pulsed neutron generator for logging

    International Nuclear Information System (INIS)

    Thibideau, F.D.

    1977-01-01

    A pulsed neutron generator for uranium logging is described. This generator is one component of a prototype uranium logging probe which is being developed by SLA to detect, and assay, uranium by borehole logging. The logging method is based on the measurement of epithermal neutrons resulting from the prompt fissioning of uranium from a pulsed source of 17.6 MeV neutrons. An objective of the prototype probe was that its diameter not exceed 2.75 inches, which would allow its use in conventional rotary drill holes of 4.75-inch diameter. This restriction limited the generator to a maximum 2.375-inch diameter. The performance requirements for the neutron generator specified that it operate with a nominal output of 5 x 10 6 neutrons/pulse at up to 100 pulses/second for a one-hour period. The development of a neutron generator meeting the preliminary design goals was completed and two prototype models were delivered to SLA. These two generators have been used by SLA to log a number of boreholes in field evaluation of the probe. The results of the field evaluations have led to the recommendation of several changes to improve the probe's operation. Some of these changes will require additional development effort on the neutron generator. It is expected that this work will be performed during 1977. The design and operation of the first prototype neutron generators is described

  1. Hardwood log grades and lumber grade yields for factory lumber logs

    Science.gov (United States)

    Leland F. Hanks; Glenn L. Gammon; Robert L. Brisbin; Everette D. Rast

    1980-01-01

    The USDA Forest Service Standard Grades for Hardwood Factory Lumber Logs are described, and lumber grade yields for 16 species and 2 species groups are presented by log grade and log diameter. The grades enable foresters, log buyers, and log sellers to select and grade those log suitable for conversion into standard factory grade lumber. By using the apropriate lumber...

  2. The log S -log N distribution of gamma ray brust

    International Nuclear Information System (INIS)

    Yamagami, Takamasa; Nishimura, Jun; Fujii, Masami

    1982-01-01

    The relation between the size S and the frequency N of gamma ray burst has been studied. This relation may be determined from the celestial distribution of gamma ray burst sources. The present analysis gives that the log S - log N relation for any direction is determined by the celestial distribution of gamma ray burst sources. The observed bursts were analyzed. The celestial distribution of gamma ray burst sources was observed by the satellites of USSR. The results showed that the distribution seemed to be isotropic. However, the calculated log S - log N relation based on the isotropic distribution wasF in disagreement with the observed ones. As the result of analysis, it was found that the observed bursts missed low energy part because of the threshold of detectors. The levels of discrimination of detection were not clear. When a proper threshold level is set for each type of burst, and the size of bursts is determined, the above mentioned discrepancy will be deleted regardless of luminosity and the spatial distribution of bursts. (Kato, T.)

  3. Mud Logging; Control geologico en perforaciones petroliferas (Mud Logging)

    Energy Technology Data Exchange (ETDEWEB)

    Pumarega Lafuente, J.C.

    1994-12-31

    Mud Logging is an important activity in the oil field and it is a key job in drilling operations, our duties are the acquisition, collection and interpretation of the geological and engineering data at the wellsite, also inform the client immediately of any significant changes in the well. (Author)

  4. Borehole logging for uranium exploration

    International Nuclear Information System (INIS)

    1982-01-01

    The present text has been prepared taking into account the requirements of both developing countries, which might be at an incipient stage of uranium exploration, and industrialized countries, where more advanced exploration and resource evaluation techniques are commonly in use. While it was felt necessary to include some discussion of exploration concepts and fundamental physical principles underlying various logging methods, it was not the intention of the consultants to provide a thorough, detailed explanation of the various techniques, or even to give a comprehensive listing thereof. However, a list of references has been included, and it is strongly recommended that the serious student of mineral logging consult this list for further guidance

  5. Pulsed neutron porosity logging system

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

    1978-01-01

    An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector, and a fast neutron detector is moved through a borehole. Repetitive bursts of neutrons irradiate the earth formations and, during the bursts, the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. The fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity

  6. Logging Work Injuries in Appalachia

    Science.gov (United States)

    Charles H. Wolf; Gilbert P. Dempsey

    1978-01-01

    Logging accidents are costly. They may bring pain to injured workers, hardship to their families, and higher insurance premiums and lower productivity to their employers. Our analysis of 1,172 injuries in central Appalachia reveals that nearly half of all time lost-and almost all fatalities-resulted from accidents during felling and unloading. The largest proportion of...

  7. Log files for testing usability

    NARCIS (Netherlands)

    Klein Teeselink, G.; Siepe, A.H.M.; Pijper, de J.R.

    1999-01-01

    The aim of this study is to gain insight in the usefulness of log file analysis as a method to evaluate the usability of individual interface components and their influence on the usability of the overall user interface. We selected a music player as application, with four different interfaces and

  8. Unification of acoustic drillhole logging data

    International Nuclear Information System (INIS)

    Oehman, I.; Palmen, J.; Heikkinen, E.

    2009-04-01

    Posiva Oy prepares for disposal of spent nuclear fuel in bedrock in Olkiluoto, Eurajoki. This is in accordance of the application filed in 1999, the Decision-in-Principle of the State Council in 2000, and ratification by the Parliament in 2001. The site characterization at Olkiluoto has included comprehensive geological, hydrological, geochemical and geophysical investigations airborne, on ground and in drillholes since 1988. One of key techniques in geophysical drillhole surveys has been acoustic full waveform logging, which has been implemented since 1994. Various tools have been used in acquisition of acoustic data and several processing techniques have been applied. The logging work and processing to P and S wave velocities has been previously carried out on single drillhole basis. Comparisons to actual values and levels have not been made, and the results have not been calibrated. Therefore results for different drillholes have not been comparable. Resolution of the P and S wave velocity has been rather coarse, and depth correlation to the core data has been on tentative level. As the investigation data has been accumulating, it has become possible to correlate the results to geological and laboratory control data and to calibrate the results of separate measurement campaigns and different drillholes together onto same reference level and resolution. The presented technique has been applied for drillhole OL-KR29 onwards and has set the processing standard, settings and reference levels for later surveys. This approach will further assist the application of the method for mapping and numerical description of lithology variation and possible effect of alteration and deformation on it. Further on, the P and S wave velocity data together with density can be used in computing of dynamic in situ rock mechanical parameters, and possibly in correlating rock strength laboratory data to P and S wave velocity logging data. The acoustic logging data from drillholes OL-KR1

  9. Hardwood log supply: a broader perspective

    Science.gov (United States)

    Iris Montague; Adri Andersch; Jan Wiedenbeck; Urs. Buehlmann

    2015-01-01

    At regional and state meetings we talk with others in our business about the problems we face: log exports, log quality, log markets, logger shortages, cash flow problems, the weather. These are familiar talking points and real and persistent problems. But what is the relative importance of these problems for log procurement in different regions of...

  10. Unsupervised signature extraction from forensic logs

    NARCIS (Netherlands)

    Thaler, S.M.; Menkovski, V.; Petkovic, M.; Altun, Y.; Das, K.; Mielikäinen, T.; Malerba, D.; Stefanowski, J.; Read, J.; Žitnik, M.; Ceci, M.

    2017-01-01

    Signature extraction is a key part of forensic log analysis. It involves recognizing patterns in log lines such that log lines that originated from the same line of code are grouped together. A log signature consists of immutable parts and mutable parts. The immutable parts define the signature, and

  11. A method of estimating log weights.

    Science.gov (United States)

    Charles N. Mann; Hilton H. Lysons

    1972-01-01

    This paper presents a practical method of estimating the weights of logs before they are yarded. Knowledge of log weights is required to achieve optimum loading of modern yarding equipment. Truckloads of logs are weighed and measured to obtain a local density index (pounds per cubic foot) for a species of logs. The density index is then used to estimate the weights of...

  12. Nondestructive evaluation for sorting red maple logs

    Science.gov (United States)

    Xiping Wang; Robert J. Ross; David W. Green; Karl Englund; Michael Wolcott

    2000-01-01

    Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) of logs. It is questionable whether the visual grading procedures currently used for logs adequately assess the potential quality of structural products manufactured from them, especially...

  13. Assessment of geophysical logs from borehole USW G-2, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Nelson, P.H.; Schimschal, U.

    1993-01-01

    Commercial logging contractors, Western Atlas, Schlumberger, and Edcon obtained borehole geophysical logs at the site of a potential high level nuclear waste repository at Yucca Mountain, Nevada. Drill hole USW-G2 was picked for this test of suitable logging tools and logging technology, both representing state-of-the-art technology by these commercial companies. Experience gained by analysis of existing core data and a variety of logs obtained earlier by Birdwell and Dresser Atlas served as a guide to a choice of logs to be obtained. Logs were obtained in water-filled borehole in zeolitized tuff (saturated zone) and in air-filled borehole largely in unaltered welded tuff (unsaturated zone)

  14. Uranium logging in earth formations

    International Nuclear Information System (INIS)

    Givens, W.W.

    1979-01-01

    A technique is provided for assaying the formations surrounding a borehole for uranium. A borehole logging tool cyclically irradiates the formations with neutrons and responds to neutron fluxes produced during the period of time that prompt neutrons are being produced by the neutron fission of uranium in the formations. A borehole calibration tool employs a steady-state (continuous output) neutron source, firstly, to produce a response to neutron fluxes in models having known concentrations of uranium and, secondly, to to produce a response to neutron fluxes in the formations surrounding the borehole. The neutron flux responses of the borehole calibration tool in both the model and the formations surrounding the borehole are utilized to correct the neutron flux response of the borehole logging tool for the effects of epithermal/thermal neutron moderation, scattering, and absorption within the borehole itself

  15. Logística empresarial

    OpenAIRE

    Feres Sahid

    1987-01-01

    RESUMEN El concepto logístico, se pudo ver reflejado con exactitud desde el punto de vista etimológico e histórico a través de la revista de la E.A.N; ya que  tiene cierto carácter militar que lo hace característico a la gestión empresarial y de esto se formula un debate definitivo de este concepto.

  16. Chemical logging of geothermal wells

    Science.gov (United States)

    Allen, C.A.; McAtee, R.E.

    The presence of geothermal aquifers can be detected while drilling in geothermal formations by maintaining a chemical log of the ratio of the concentrations of calcium to carbonate and bicarbonate ions in the return drilling fluid. A continuous increase in the ratio of the concentrations of calcium to carbonate and bicarbonate ions is indicative of the existence of a warm or hot geothermal aquifer at some increased depth.

  17. Audit Log for Forensic Photography

    Science.gov (United States)

    Neville, Timothy; Sorell, Matthew

    We propose an architecture for an audit log system for forensic photography, which ensures that the chain of evidence of a photograph taken by a photographer at a crime scene is maintained from the point of image capture to its end application at trial. The requirements for such a system are specified and the results of experiments are presented which demonstrate the feasibility of the proposed approach.

  18. Logística empresarial

    Directory of Open Access Journals (Sweden)

    Feres Sahid

    1987-04-01

    Full Text Available RESUMEN El concepto logístico, se pudo ver reflejado con exactitud desde el punto de vista etimológico e histórico a través de la revista de la E.A.N; ya que  tiene cierto carácter militar que lo hace característico a la gestión empresarial y de esto se formula un debate definitivo de este concepto.

  19. Neutron capture in borehole logging

    International Nuclear Information System (INIS)

    Randall, R.R.

    1981-01-01

    The use is described of a pulsed source of fast neutrons and a radiation detector to measure the thermal neutron population decay rate in a well logging instrument. The macroscopic neutron absorption cross-section is calculated by taking the natural logarithm of the ratio of the detected radiation counts occurring within two measurement intervals of fixed duration and starting at a fixed time after a neutron burst. (U.K.)

  20. Borehole logging in uranium exploration

    International Nuclear Information System (INIS)

    Kulkarni, N.H.

    1992-01-01

    The ultimate objective of exploration by drilling as far as Atomic Minerals Division is concerned is to locate the ore zone in the subsurface, draw samples and analyze them for their metal content. The presence of the ore zone is also indicated by gamma-ray logging of the borehole. A gamma-ray detector is lowered in the borehole and precise depth and grade of the ore zone is established. This helps the geologist in correlating the ore horizon with the surface outcrop or the ore zone intercepted in adjoining boreholes and in deciding about further drilling and location of boreholes. Most commonly, total gamma measurements are made although some units capable of measuring the gamma-ray spectrum are also in use. It is possible to know if the mineralization is due to uranium without waiting for the laboratory results. The present write up gives a brief account of the principles, equipment and methods of borehole gamma-ray logging including density and self-potential logging. (author). 8 refs., 5 figs

  1. Nuclear

    International Nuclear Information System (INIS)

    2014-01-01

    This document proposes a presentation and discussion of the main notions, issues, principles, or characteristics related to nuclear energy: radioactivity (presence in the environment, explanation, measurement, periods and activities, low doses, applications), fuel cycle (front end, mining and ore concentration, refining and conversion, fuel fabrication, in the reactor, back end with reprocessing and recycling, transport), the future of the thorium-based fuel cycle (motivations, benefits and drawbacks), nuclear reactors (principles of fission reactors, reactor types, PWR reactors, BWR, heavy-water reactor, high temperature reactor of HTR, future reactors), nuclear wastes (classification, packaging and storage, legal aspects, vitrification, choice of a deep storage option, quantities and costs, foreign practices), radioactive releases of nuclear installations (main released radio-elements, radioactive releases by nuclear reactors and by La Hague plant, gaseous and liquid effluents, impact of releases, regulation), the OSPAR Convention, management and safety of nuclear activities (from control to quality insurance, to quality management and to sustainable development), national safety bodies (mission, means, organisation and activities of ASN, IRSN, HCTISN), international bodies, nuclear and medicine (applications of radioactivity, medical imagery, radiotherapy, doses in nuclear medicine, implementation, the accident in Epinal), nuclear and R and D (past R and D programmes and expenses, main actors in France and present funding, main R and D axis, international cooperation)

  2. Dynamic Planar Convex Hull with Optimal Query Time and O(log n · log log n ) Update Time

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Jakob, Riko

    2000-01-01

    The dynamic maintenance of the convex hull of a set of points in the plane is one of the most important problems in computational geometry. We present a data structure supporting point insertions in amortized O(log n · log log log n) time, point deletions in amortized O(log n · log log n) time......, and various queries about the convex hull in optimal O(log n) worst-case time. The data structure requires O(n) space. Applications of the new dynamic convex hull data structure are improved deterministic algorithms for the k-level problem and the red-blue segment intersection problem where all red and all...

  3. Data Mining of Network Logs

    Science.gov (United States)

    Collazo, Carlimar

    2011-01-01

    The statement of purpose is to analyze network monitoring logs to support the computer incident response team. Specifically, gain a clear understanding of the Uniform Resource Locator (URL) and its structure, and provide a way to breakdown a URL based on protocol, host name domain name, path, and other attributes. Finally, provide a method to perform data reduction by identifying the different types of advertisements shown on a webpage for incident data analysis. The procedures used for analysis and data reduction will be a computer program which would analyze the URL and identify and advertisement links from the actual content links.

  4. Neutron borehole logging correction technique

    International Nuclear Information System (INIS)

    Goldman, L.H.

    1978-01-01

    In accordance with an illustrative embodiment of the present invention, a method and apparatus is disclosed for logging earth formations traversed by a borehole in which an earth formation is irradiated with neutrons and gamma radiation produced thereby in the formation and in the borehole is detected. A sleeve or shield for capturing neutrons from the borehole and producing gamma radiation characteristic of that capture is provided to give an indication of the contribution of borehole capture events to the total detected gamma radiation. It is then possible to correct from those borehole effects the total detected gamma radiation and any earth formation parameters determined therefrom

  5. Benchmark neutron porosity log calculations

    International Nuclear Information System (INIS)

    Little, R.C.; Michael, M.; Verghese, K.; Gardner, R.P.

    1989-01-01

    Calculations have been made for a benchmark neutron porosity log problem with the general purpose Monte Carlo code MCNP and the specific purpose Monte Carlo code McDNL. For accuracy and timing comparison purposes the CRAY XMP and MicroVax II computers have been used with these codes. The CRAY has been used for an analog version of the MCNP code while the MicroVax II has been used for the optimized variance reduction versions of both codes. Results indicate that the two codes give the same results within calculated standard deviations. Comparisons are given and discussed for accuracy (precision) and computation times for the two codes

  6. 29 CFR 1918.88 - Log operations.

    Science.gov (United States)

    2010-07-01

    ...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Handling Cargo § 1918.88 Log operations. (a) Working in..., the employer shall ensure that employees remain clear of areas where logs being dumped could strike...

  7. Artificial intelligence approach to interwell log correlation

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jong-Se [Korea Maritime University, Pusan(Korea); Kang, Joo Myung [Seoul National University, Seoul(Korea); Kim, Jung Whan [Korea National Oil Corp., Anyang(Korea)

    2000-04-30

    This paper describes a new approach to automated interwell log correlation using artificial intelligence and principal component analysis. The approach to correlate wire line logging data is on the basis of a large set of subjective rules that are intended to represent human logical processes. The data processed are mainly the qualitative information such as the characteristics of the shapes extracted along log traces. The apparent geologic zones are identified by pattern recognition for the specific characteristics of log trace collected as a set of objects by object oriented programming. The correlation of zones between wells is made by rule-based inference program. The reliable correlation can be established from the first principal component logs derived from both the important information around well bore and the largest common part of variances of all available well log data. Correlation with field log data shows that this approach can make interwell log correlation more reliable and accurate. (author). 6 refs., 7 figs.

  8. Face logging in Copenhagen Limestone, Denmark

    DEFF Research Database (Denmark)

    Jakobsen, Lisa; Foged, Niels Nielsen; Erichsen, Lars

    2015-01-01

    tunnel in Copenhagen more than 2.5 km face logs were made in 467 locations at underground stations, shafts, caverns and along bored tunnels. Over 160 geotechnical boreholes, many with geophysical logging were executed prior to construction works. The bedrock consists of Paleogene "Copenhagen limestone......The requirement for excavation support can be assessed from face logging. Face logs can also improve our knowledge of lithological and structural conditions within bedrock and supplement information from boreholes and geophysical logs. During the construction of 8 km metro tunnel and 4 km heating....... The induration degrees recorded in face logs and boreholes are compared and correlated. Distinct geophysical log markers are used to divide the limestone into three units. These marker horizons are correlated between face logs and geotechnical boreholes. A 3D model of the strength variations recorded within...

  9. Tucker Wireline Open Hole Wireline Logging; FINAL

    International Nuclear Information System (INIS)

    Milliken, M.

    2002-01-01

    The Tucker Wireline unit ran a suite of open hole logs right behind the RMOTC logging contractor for comparison purposes. The tools included Dual Laterolog, Phased Induction, BHC Sonic, and Density-Porosity

  10. Selective logging in the Brazilian Amazon.

    Science.gov (United States)

    G. P. Asner; D. E. Knapp; E. N. Broadbent; P. J. C. Oliveira; M Keller; J. N. Silva

    2005-01-01

    Amazon deforestation has been measured by remote sensing for three decades. In comparison, selective logging has been mostly invisible to satellites. We developed a large-scale, high-resolution, automated remote-sensing analysis of selective logging in the top five timber-producing states of the Brazilian Amazon. Logged areas ranged from 12,075 to 19,823 square...

  11. Linking log quality with product performance

    Science.gov (United States)

    D. W. Green; Robert Ross

    1997-01-01

    In the United States, log grading procedures use visual assessment of defects, in relation to the log scaling diameter, to estimate the yield of lumber that maybe expected from the log. This procedure was satisfactory when structural grades were based only on defect size and location. In recent years, however, structural products have increasingly been graded using a...

  12. Selective logging and its relation to deforestation

    Science.gov (United States)

    Gregory P. Asner; Michael Keller; Marco Lentini; Frank Merry; Souza Jr. Carlos

    2009-01-01

    Selective logging is a major contributor to the social, economic, and ecological dynamics of Brazilian Amazonia. Logging activities have expanded from low-volume floodplain harvests in past centuries to high-volume operations today that take about 25 million m3 of wood from the forest each year. The most common high-impact conventional and often illegal logging...

  13. Pacific Rim log trade: determinants and trends.

    Science.gov (United States)

    Donald F. Flora; Andrea L. Anderson; Wendy J. McGinnls

    1991-01-01

    Pacific Rim trade in softwood logs amounts to about $3 billion annually, of which the U.S. share is about $2 billion. Log exporting is a significant part of the forest economy in the Pacific Northwest. The 10 major Pacific Rim log-trading client and competitor countries differ widely in their roles in trade and in their policies affecting the industry.

  14. Well logging radioactive detector assembly

    International Nuclear Information System (INIS)

    Osburn, T.D.

    1992-01-01

    This patent describes a well logging instrument of the type having a radioactive logging sub having a sealed chamber and have a radioactive source for emitting radioactive energy into the well formation, the instrument having a radioactive energy detector for detecting gamma rays resulting from the emission of the radioactive energy into the well formation, and means for pressing the sub against the well of the well, an improved Dewar flask for the detector. It comprises: an inner housing formed of titanium and containing the detector; an outer housing formed of titanium, having a cylindrical side wall surrounding the inner housing and separated by a clearance which is evacuated, the outer housing being located within the sealed chamber in the sub of the instrument; a window section formed in the side wall of the outer housing adjacent the detector and on a side of the side wall closest to the wall of the well when the sub is pressed against the wall of the well; and wherein the inner housing has a cylindrical side wall that is of lesser wall thickness than the wall thickness of the side wall of the outer housing other than in the window section

  15. Analysis of log rate noise in Ontario's CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hinds, H.W. [Dynamic Simulation and Analysis Corp., Deep River, Ontario (Canada); Banica, C.; Arguner, D. [Ontario Power Generation, Ajax, Ontario (Canada); Scharfenberg, R. [Bruce Power, Tiverton, Ontario (Canada)

    2007-07-01

    In the fall of 2003, the operators noticed that in the recently-refurbished Bruce A Shutdown System no. 1 (SDS1) the noise level in Log Rate signals were much larger than before. At the request of the Canadian Nuclear Safety Commission (CNSC), all Canadian CANDU reactors took action to characterize their Log Rate noise. Staff of the Inspection and Maintenance Services division of Ontario Power Generation (OPG) has collected high-speed high-accuracy noise data from nearly all 16 Ontario reactors, either as part of routine measurements before planned outages or as a dedicated noise recording. This paper gives the results of examining a suitable subset of this data, with respect to the characteristics and possible causes of Log Rate noise. The reactor and instrumentation design is different at each station: the locations of the moderator injection nozzles, the location of the ion chambers for each system, and the design of the Log Rate amplifiers. It was found that the Log noise (source of Log Rate noise) was much larger for those ion chambers in the path of the moderator injection nozzles, compared to those which were not in the path. This 'extra' Log noise would then be either attenuated or amplified depending on the transfer function (time constants) of the Log Rate amplifier. It was also observed that most of the Log and Log Rate noise is independent of any other signal measured. Although all CANDU reactors in Ontario have Log and Log Rate noise, the Bruce A SDS1 system has the largest amount of Log Rate noise, because (a) its SDS1 (and RRS) ion chambers are at the top of the reactor in the path of the moderator injection nozzles, and (b) its SDS1 Log Rate amplifiers have the smallest time constants. (author)

  16. Time interval approach to the pulsed neutron logging method

    International Nuclear Information System (INIS)

    Zhao Jingwu; Su Weining

    1994-01-01

    The time interval of neighbouring neutrons emitted from a steady state neutron source can be treated as that from a time-dependent neutron source. In the rock space, the neutron flux is given by the neutron diffusion equation and is composed of an infinite terms. Each term s composed of two die-away curves. The delay action is discussed and used to measure the time interval with only one detector in the experiment. Nuclear reactions with the time distribution due to different types of radiations observed in the neutron well-logging methods are presented with a view to getting the rock nuclear parameters from the time interval technique

  17. Semi-automatic logarithmic converter of logs

    International Nuclear Information System (INIS)

    Gol'dman, Z.A.; Bondar's, V.V.

    1974-01-01

    Semi-automatic logarithmic converter of logging charts. An original semi-automatic converter was developed for use in converting BK resistance logging charts and the time interval, ΔT, of acoustic logs from a linear to a logarithmic scale with a specific ratio for subsequent combining of them with neutron-gamma logging charts in operative interpretation of logging materials by a normalization method. The converter can be used to increase productivity by giving curves different from those obtained in manual, pointwise processing. The equipment operates reliably and is simple in use. (author)

  18. Well log characterization of natural gas-hydrates

    Science.gov (United States)

    Collett, Timothy S.; Lee, Myung W.

    2012-01-01

    In the last 25 years there have been significant advancements in the use of well-logging tools to acquire detailed information on the occurrence of gas hydrates in nature: whereas wireline electrical resistivity and acoustic logs were formerly used to identify gas-hydrate occurrences in wells drilled in Arctic permafrost environments, more advanced wireline and logging-while-drilling (LWD) tools are now routinely used to examine the petrophysical nature of gas-hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. Resistivity- and acoustic-logging tools are the most widely used for estimating the gas-hydrate content (i.e., reservoir saturations) in various sediment types and geologic settings. Recent integrated sediment coring and well-log studies have confirmed that electrical-resistivity and acoustic-velocity data can yield accurate gas-hydrate saturations in sediment grain-supported (isotropic) systems such as sand reservoirs, but more advanced log-analysis models are required to characterize gas hydrate in fractured (anisotropic) reservoir systems. New well-logging tools designed to make directionally oriented acoustic and propagation-resistivity log measurements provide the data needed to analyze the acoustic and electrical anisotropic properties of both highly interbedded and fracture-dominated gas-hydrate reservoirs. Advancements in nuclear magnetic resonance (NMR) logging and wireline formation testing (WFT) also allow for the characterization of gas hydrate at the pore scale. Integrated NMR and formation testing studies from northern Canada and Alaska have yielded valuable insight into how gas hydrates are physically distributed in sediments and the occurrence and nature of pore fluids(i.e., free water along with clay- and capillary-bound water) in gas-hydrate-bearing reservoirs. Information on the distribution of gas hydrate at the pore scale has provided invaluable insight on the mechanisms

  19. A Universal Logging System for LHCb Online

    International Nuclear Information System (INIS)

    Nikolaidis, Fotis; Brarda, Loic; Garnier, Jean-Christophe; Neufeld, Niko

    2011-01-01

    A log is recording of system's activity, aimed to help system administrator to traceback an attack, find the causes of a malfunction and generally with troubleshooting. The fact that logs are the only information an administrator may have for an incident, makes logging system a crucial part of an IT infrastructure. In large scale infrastructures, such as LHCb Online, where quite a few GB of logs are produced daily, it is impossible for a human to review all of these logs. Moreover, a great percentage of them as just n oise . That makes clear that a more automated and sophisticated approach is needed. In this paper, we present a low-cost centralized logging system which allow us to do in-depth analysis of every log.

  20. A neutron well logging system

    International Nuclear Information System (INIS)

    1980-01-01

    A pulsed neutron well logging system using a sealed off neutron generator tube is provided with a programmable digital neutron output control system. The control system monitors the target beam current and compares a function of this current with a pre-programmed control function to develop a control signal for the neutron generator. The control signal is used in a series regulator to control the average replenisher current of the neutron generator tube. The programmable digital control system of the invention also provides digital control signals as a function of time to provide ion source voltages. This arrangement may be utilized to control neutron pulses durations and repetition rates or to produce other modulated wave forms for intensity modulating the output of the neutron generator as a function of time. (Auth.)

  1. Decomposable log-linear models

    DEFF Research Database (Denmark)

    Eriksen, Poul Svante

    can be characterized by a structured set of conditional independencies between some variables given some other variables. We term the new model class decomposable log-linear models, which is illustrated to be a much richer class than decomposable graphical models.It covers a wide range of non...... The present paper considers discrete probability models with exact computational properties. In relation to contingency tables this means closed form expressions of the maksimum likelihood estimate and its distribution. The model class includes what is known as decomposable graphicalmodels, which......-hierarchical models, models with structural zeroes, models described by quasi independence and models for level merging. Also, they have a very natural interpretation as they may be formulated by a structured set of conditional independencies between two events given some other event. In relation to contingency...

  2. Well logging, atom and geology

    International Nuclear Information System (INIS)

    Serra, O.

    1994-01-01

    Well logging techniques exploit interactions of gamma photons and neutrons with atoms. Interactions of neutrons of different energies with atoms allow the detection and evaluation of the weight percentage of several elements composing the rocks (C, O, Si, Ca, Fe, S); spectrometry of gamma rays produced by thermal neutron absorption allows for the weight percentage determination of Si, Ca, Fe, S, Cl, H, Ti and Gd, etc. High resolution detectors (germanium doped by Li, at liquid nitrogen temperature) allow the recognition of more elements. Other techniques involving neutrons consist in determining the population in epithermal neutrons at a certain distance of the neutron source (measurement of the hydrogen index). By analyzing the intensity of the gamma flux produced by Compton scattering, the electronic and bulk densities of the rocks are measured. All these data lead to the detection and evaluation of ore deposits (uranium and potassium) and coal, and determination of the lithology, the main minerals composing the rocks, petrophysical properties... 1 fig

  3. Geomicrobial Optical Logging Detectors (GOLD)

    Science.gov (United States)

    Bramall, N. E.; Stoker, C. R.; Price, P. B.; Coates, J. D.; Allamandola, L. J.; Mattioda, A. L.

    2008-12-01

    We will present concepts for downhole instrumentation that could be used in the Deep Underground Science and Engineering Laboratory (DUSEL). We envision optical borehole-logging instruments that could monitor bacterial concentration, mineralogy, aromatic organics, temperature and oxygen concentration, allowing for the in situ monitoring of time-dependent microbial and short-scale geologic processes and provide valuable in situ data on stratigraphy to supplement core analyses, especially where instances of missing or damaged core sections make such studies difficult. Incorporated into these instruments will be a sampling/inoculation tool to allow for the recovery and/or manipulation of particularly interesting sections of the borehole wall for further study, enabling a series of microbiological studies. The borehole tools we will develop revolve around key emerging technologies and methods, some of which are briefly described below: 1) Autofluorescence Spectroscopy: Building on past instruments, we will develop a new borehole logger that searches for microbial life and organics using fluorescence spectroscopy. Many important organic compounds (e.g. PAHs) and biomolecules (e.g. aromatic amino acids, proteins, methanogenic coenzymes) fluoresce when excited with ultraviolet and visible light. Through the careful selection of excitation wavelength(s) and temporal gating parameters, a borehole logging instrument can detect and differentiate between these different compounds and the mineral matrix in which they exist. 2) Raman Spectroscopy: Though less sensitive than fluorescence spectroscopy, Raman spectroscopy is more definitive: it can provide important mineral phase distribution/proportions and other chemical data enabling studies of mineralogy and microbe-mineral interactions (when combined with fluorescence). 3) Borehole Camera: Imaging of the borehole wall with extended information in the UV, visible, and NIR for a more informative view can provide a lot of insight

  4. The STAR ESL, electronic shift and handover log

    Energy Technology Data Exchange (ETDEWEB)

    Hajdu, L; Lauret, J, E-mail: lbhajdu@bnl.gov

    2008-07-01

    Keeping a clear and accurate experiment log is important for any scientific experiment. The concept is certainly not new but keeping accurate while useful records for a Nuclear Physics experiment such as the Solenoidal Tracker at the Relativistic Heavy Ion Collider (STAR at RHIC) is not a priori a simple matter - STAR operates 24 hours a day for six months out of the year with more than 24 shift crews operating 16 different subsystems (some located remotely). To meet the challenge of not only logging the information but passing it in a concise manner from one shift to another, the STAR experiment has designed an Electronic Shift-Log (ESL), a flexible application written in Java and interfacing with the Data Acquisition tools, Quality Assurance reporting, Online shift crews or remote personnel and experts as well as including features such as shift change-over (or handover) forms, tailored to the sub-group of interest. We will present an overview of STAR's Electronic Log, a system that is clear, reliable, safe, consistent, easy to use and globally viewable in real time with secure connections.

  5. California-Nevada uranium logging. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    The purpose of this project was to obtain geophysical logs of industry drill holes to assess the uranium resource potential of geologic formations of interest. The work was part of the US Department of Energy's National Uranium Resource Evaluation (NURE) Program. The principal objective of the logging program was to determine radioelement grade of formations through natural gamma ray detectors. Supplementary information was obtained from resistivity (R), self-potential (SP), point resistance (RE), and neutron density (NN) logs for formation interpretation. Additional data for log interpretation was obtained from caliper logs, casing schedules, and downhole temperature. This data was obtained from well operators when available, with new logs obtained where not formerly available. This report contains a summary of the project and data obtained to date

  6. LogDet Rank Minimization with Application to Subspace Clustering

    Directory of Open Access Journals (Sweden)

    Zhao Kang

    2015-01-01

    Full Text Available Low-rank matrix is desired in many machine learning and computer vision problems. Most of the recent studies use the nuclear norm as a convex surrogate of the rank operator. However, all singular values are simply added together by the nuclear norm, and thus the rank may not be well approximated in practical problems. In this paper, we propose using a log-determinant (LogDet function as a smooth and closer, though nonconvex, approximation to rank for obtaining a low-rank representation in subspace clustering. Augmented Lagrange multipliers strategy is applied to iteratively optimize the LogDet-based nonconvex objective function on potentially large-scale data. By making use of the angular information of principal directions of the resultant low-rank representation, an affinity graph matrix is constructed for spectral clustering. Experimental results on motion segmentation and face clustering data demonstrate that the proposed method often outperforms state-of-the-art subspace clustering algorithms.

  7. Pembangkitan Data dari Distribusi Log-logistik

    Directory of Open Access Journals (Sweden)

    Aceng Komarudin Mutaqin

    2014-11-01

    Full Text Available Distribusi log-logistik merupakan salah satu distribusi yang dapat diaplikasikan untuk data mutu lingkungan. Makalah ini membahas pembangkitan data dari distribusi log-logistik mulai dari pembangunan algoritme sampai pembuatan program komputer pada perangkat lunak MATLAB. Metode pembangkitan datanya menggunakan metode inverse transform. Ada dua jenis data yang dibangkitkan, yaitu data lengkap dan data tersensor kiri. Dalam makalah ini diberikan contoh data yang dibangkitkan dari distribusi log-logistik.

  8. SNG-logs at the Bagsvaerd Lake

    International Nuclear Information System (INIS)

    Korsbech, U.

    1992-11-01

    Spectral Natural Gamma-logs (SNG) were taken in old boreholes around Bagsvaerd Lake (Zealand). The purpose of this investigation was to clarify the geologic/lithologic conditions in this region and the potential risks of waste penetration into ground water. Relationship curves for thorium, uranium and potassium concentrations are given. Some special logs which can be useful for evaluating concentration variations or transition forms among various lithological layers are collected. Appendices contain technical information on the boreholes and discussion of differences between results of SNG-logging and the conventional gamma-logging. (EG)

  9. Nuclear

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The first text deals with a new circular concerning the collect of the medicine radioactive wastes, containing radium. This campaign wants to incite people to let go their radioactive wastes (needles, tubes) in order to suppress any danger. The second text presents a decree of the 31 december 1999, relative to the limitations of noise and external risks resulting from the nuclear facilities exploitation: noise, atmospheric pollution, water pollution, wastes management and fire prevention. (A.L.B.)

  10. 32 CFR 700.846 - Status of logs.

    Science.gov (United States)

    2010-07-01

    ... Officers Afloat § 700.846 Status of logs. The deck log, the engineering log, the compass record, the bearing hooks, the engineer's bell book, and any records generated by automated data logging equipment...

  11. Method and equipment for fast transmission of a signal consisting of many data pulses by a normal well-logging cable

    International Nuclear Information System (INIS)

    Pitts, R.W. Jr.; Whatley, H.A. Jr.

    1975-01-01

    Well logging methods and equipment in general and a nuclear well logging process and apparatus in particular are presented. They increase the number of pulses which can be transmitted to the top of the well from a well logging instrument placed at the bottom, during a given time interval, by means of a processing giving two pulses for each pulse corresponding to a detection. The equipment is a double-spectrum well logging system, with near and far detectors [fr

  12. Influence of borehole-eccentred tools on wireline and logging-while-drilling sonic logging measurements

    KAUST Repository

    Pardo, David; Matuszyk, Paweł Jerzy; Torres-Verdí n, Carlos; Mora Cordova, Angel; Muga, Ignacio; Calo, Victor M.

    2013-01-01

    We describe a numerical study to quantify the influence of tool-eccentricity on wireline (WL) and logging-while-drilling (LWD) sonic logging measurements. Simulations are performed with a height-polynomial-adaptive (hp) Fourier finite-element method

  13. Log canonical thresholds of smooth Fano threefolds

    International Nuclear Information System (INIS)

    Cheltsov, Ivan A; Shramov, Konstantin A

    2008-01-01

    The complex singularity exponent is a local invariant of a holomorphic function determined by the integrability of fractional powers of the function. The log canonical thresholds of effective Q-divisors on normal algebraic varieties are algebraic counterparts of complex singularity exponents. For a Fano variety, these invariants have global analogues. In the former case, it is the so-called α-invariant of Tian; in the latter case, it is the global log canonical threshold of the Fano variety, which is the infimum of log canonical thresholds of all effective Q-divisors numerically equivalent to the anticanonical divisor. An appendix to this paper contains a proof that the global log canonical threshold of a smooth Fano variety coincides with its α-invariant of Tian. The purpose of the paper is to compute the global log canonical thresholds of smooth Fano threefolds (altogether, there are 105 deformation families of such threefolds). The global log canonical thresholds are computed for every smooth threefold in 64 deformation families, and the global log canonical thresholds are computed for a general threefold in 20 deformation families. Some bounds for the global log canonical thresholds are computed for 14 deformation families. Appendix A is due to J.-P. Demailly.

  14. Aggregation of log-linear risks

    DEFF Research Database (Denmark)

    Embrechts, Paul; Hashorva, Enkeleijd; Mikosch, Thomas Valentin

    2014-01-01

    In this paper we work in the framework of a k-dimensional vector of log-linear risks. Under weak conditions on the marginal tails and the dependence structure of a vector of positive risks, we derive the asymptotic tail behaviour of the aggregated risk {and present} an application concerning log...

  15. Synthetic rope applications in Appalachian logging

    Science.gov (United States)

    Ben D. Spong; Jingxin Wang

    2008-01-01

    New ultra-high molecular weight polyethylene rope has shown good results as a replacement for wire rope in logging applications in the western United States. A single case study trial was performed in Appalachian forest conditions to assess the appropriateness of this technology for hardwood logging applications. The study focused on use of the rope in West Virginia...

  16. Palm distributions for log Gaussian Cox processes

    DEFF Research Database (Denmark)

    Coeurjolly, Jean-Francois; Møller, Jesper; Waagepetersen, Rasmus

    This paper reviews useful results related to Palm distributions of spatial point processes and provides a new result regarding the characterization of Palm distributions for the class of log Gaussian Cox processes. This result is used to study functional summary statistics for a log Gaussian Cox...

  17. Log-binomial models: exploring failed convergence.

    Science.gov (United States)

    Williamson, Tyler; Eliasziw, Misha; Fick, Gordon Hilton

    2013-12-13

    Relative risk is a summary metric that is commonly used in epidemiological investigations. Increasingly, epidemiologists are using log-binomial models to study the impact of a set of predictor variables on a single binary outcome, as they naturally offer relative risks. However, standard statistical software may report failed convergence when attempting to fit log-binomial models in certain settings. The methods that have been proposed in the literature for dealing with failed convergence use approximate solutions to avoid the issue. This research looks directly at the log-likelihood function for the simplest log-binomial model where failed convergence has been observed, a model with a single linear predictor with three levels. The possible causes of failed convergence are explored and potential solutions are presented for some cases. Among the principal causes is a failure of the fitting algorithm to converge despite the log-likelihood function having a single finite maximum. Despite these limitations, log-binomial models are a viable option for epidemiologists wishing to describe the relationship between a set of predictors and a binary outcome where relative risk is the desired summary measure. Epidemiologists are encouraged to continue to use log-binomial models and advocate for improvements to the fitting algorithms to promote the widespread use of log-binomial models.

  18. LHCb Online Log Analysis and Maintenance System

    CERN Document Server

    Garnier, J-C

    2011-01-01

    History has shown, many times computer logs are the only information an administrator may have for an incident, which could be caused either by a malfunction or an attack. Due to the huge amount of logs that are produced from large-scale IT infrastructures, such as LHCb Online, critical information may be overlooked or simply be drowned in a sea of other messages. This clearly demonstrates the need for an automatic system for long-term maintenance and real time analysis of the logs. We have constructed a low cost, fault tolerant centralized logging system which is able to do in-depth analysis and cross-correlation of every log. This system is capable of handling O(10000) different log sources and numerous formats, while trying to keep the overhead as low as possible. It provides log gathering and management, Offline analysis and online analysis. We call Offline analysis the procedure of analyzing old logs for critical information, while Online analysis refer to the procedure of early alerting and reacting. ...

  19. A semantic perspective on query log analysis

    NARCIS (Netherlands)

    Hofmann, K.; de Rijke, M.; Huurnink, B.; Meij, E.

    2009-01-01

    We present our views on the CLEF log file analysis task. We argue for a task definition that focuses on the semantic enrichment of query logs. In addition, we discuss how additional information about the context in which queries are being made could further our understanding of users’ information

  20. Utilization and cost for animal logging operations

    Science.gov (United States)

    Suraj P. Shrestha; Bobby L. Lanford

    2001-01-01

    Forest harvesting with animals is a labor-intensive operation. Due to the development of efficient machines and high volume demands from the forest products industry, mechanization of logging developed very fast, leaving behind the traditional horse and mule logging. It is expensive to use machines on smaller woodlots, which require frequent moves if mechanically...

  1. Data logging system upgrade for Indus accelerator

    International Nuclear Information System (INIS)

    Mishra, R.; Merh, B.N.; Agrawal, R.K.; Fatnani, P.; Navathe, C.P.; Pal, S.

    2012-01-01

    An accelerator has various subsystems like Magnet Power Supply, Beam Diagnostics and Vacuum etc. which are required to work in a stable manner to ensure required machine performance. Logging of system parameters at a faster rate plays a crucial role in analysing and understanding machine behaviour. Logging all the machine parameters consistently at the rate of typically more than 1 Hz has been the aim of a recent data logging system upgrade. Nearly ten thousand parameters are being logged at varying intervals of one second to one minute in Indus accelerator complex. The present logging scheme is augmented to log all these parameters at a rate equal to or more than 1 Hz. The database schema is designed according to the data type of the parameter. The data is distributed into historical table and intermediate table which comprises of recent data. Machine control applications read the parameter values from the control system and store them into the text files of finite time duration for each sub-system. The logging application of each sub-system passes these text files to database for bulk insertion. The detail design of database, logging scheme and its architecture is presented in the paper. (author)

  2. Impacts of extended working hours in logging

    Science.gov (United States)

    Dana Mitchell; Tom Gallagher

    2008-01-01

    Last year at the 2007 AIM in Minneapolis, MN, the authors presented the human factors impacts to consider when implementing extended working hours in the logging industry. In a continuation of this project, we have researched existing literature to identify possible actions that logging business owners can take to reduce the impact of extended working hours on their...

  3. Neutron logging reliability techniques and apparatus

    International Nuclear Information System (INIS)

    Johnstone, C.W.

    1978-01-01

    This invention relates in general to neutron logging of earth formations, and in particular, to novel apparatus and procedures for determining the validity, or reliability, of data derived at least in part by logging neutron characteristics of earth formations and, if desired, for affording verifiably accurate indications of such data

  4. Neutron logging reliability techniques and apparatus

    International Nuclear Information System (INIS)

    Johnstone, C.W.

    1974-01-01

    This invention relates in general to neutron logging of earth formations, and in particular, to novel apparatus and procedures for determining the validity, or reliability, of data derived at least in part by logging neutron characteristics of earth formations and, if desired, for affording verifiably accurate indications of such data. (author)

  5. Logging methods and peeling of Aspen

    Science.gov (United States)

    T. Schantz-Hansen

    1948-01-01

    The logging of forest products is influenced by many factors, including the size of the trees, density of the stand, the soundness of the trees, size of the area logged, topography and soil, weather conditions, the degree of utilization, the skill of the logger and the equipment used, the distance from market, etc. Each of these factors influences not only the method...

  6. Log Analysis Using Splunk Hadoop Connect

    Science.gov (United States)

    2017-06-01

    23 A. INPUT SELECTION ...Conversion Resource Consumption .............................................. 28 Figure 8. Distribution of Events in Years...running a logging service puts a performance tax on the system and may cause the degradation of performance. More thorough 8 logging will cause a

  7. Grading sugar pine saw logs in trees.

    Science.gov (United States)

    John W. Henley

    1972-01-01

    Small limbs and small overgrown limbs cause problems when grading saw logs in sugar pine trees. Surface characteristics and lumber recovery information for 426 logs from 64 sugar pine trees were examined. Resulting modifications in the grading specification that allow a grader to ignore small limbs and small limb indicators do not appear to decrease the performance of...

  8. Analysis of RIA standard curve by log-logistic and cubic log-logit models

    International Nuclear Information System (INIS)

    Yamada, Hideo; Kuroda, Akira; Yatabe, Tami; Inaba, Taeko; Chiba, Kazuo

    1981-01-01

    In order to improve goodness-of-fit in RIA standard analysis, programs for computing log-logistic and cubic log-logit were written in BASIC using personal computer P-6060 (Olivetti). Iterative least square method of Taylor series was applied for non-linear estimation of logistic and log-logistic. Hear ''log-logistic'' represents Y = (a - d)/(1 + (log(X)/c)sup(b)) + d As weights either 1, 1/var(Y) or 1/σ 2 were used in logistic or log-logistic and either Y 2 (1 - Y) 2 , Y 2 (1 - Y) 2 /var(Y), or Y 2 (1 - Y) 2 /σ 2 were used in quadratic or cubic log-logit. The term var(Y) represents squares of pure error and σ 2 represents estimated variance calculated using a following equation log(σ 2 + 1) = log(A) + J log(y). As indicators for goodness-of-fit, MSL/S sub(e)sup(2), CMD% and WRV (see text) were used. Better regression was obtained in case of alpha-fetoprotein by log-logistic than by logistic. Cortisol standard curve was much better fitted with cubic log-logit than quadratic log-logit. Predicted precision of AFP standard curve was below 5% in log-logistic in stead of 8% in logistic analysis. Predicted precision obtained using cubic log-logit was about five times lower than that with quadratic log-logit. Importance of selecting good models in RIA data processing was stressed in conjunction with intrinsic precision of radioimmunoassay system indicated by predicted precision. (author)

  9. Processing of gamma-ray spectrometric logs

    International Nuclear Information System (INIS)

    Umiastowski, K.; Dumesnil, P.

    1984-10-01

    CEA (Commissariat a l'Energie Atomique) has developped a gamma-ray spectrometric tool, containing an analog-to-digital converter. This new tool permits to perform very precise uranium logs (natural gamma-ray spectrometry), neutron activation logs and litho-density logs (gamma-gamma spectrometric logs). Specific processing methods were developped to treate the particular problems of down-hole gamma-ray spectrometry. Extraction of the characteristic gamma-ray peak, even if they are superposed on the background radiation of very high intensity, is possible. This processing methode enables also to obtain geological informations contained in the continuous background of the spectrum. Computer programs are written in high level language for SIRIUS (VICTOR) and APOLLO computers. Exemples of uranium and neutron activation logs treatment are presented [fr

  10. LOG2MARKUP: State module to transform a Stata text log into a markup document

    DEFF Research Database (Denmark)

    2016-01-01

    log2markup extract parts of the text version from the Stata log command and transform the logfile into a markup based document with the same name, but with extension markup (or otherwise specified in option extension) instead of log. The author usually uses markdown for writing documents. However...

  11. Processing well logging data, for example for verification and calibration of well logs

    International Nuclear Information System (INIS)

    Suau, J.; Boutemy, Y.

    1981-01-01

    A method is described of machine processing well logging data derived from borehole exploring devices which investigate earth formations traversed by boreholes. The method can be used for verifying and recalibrating logs, reconstructing missing logs and combining the data to form a statistical model of the traversed earth formations. (U.K.)

  12. Method and apparatus for producing a porosity log of a subsurface formation corrected for detector standoff

    International Nuclear Information System (INIS)

    Allen, L.S.; Mills, W.R.; Stromswold, D.C.

    1991-01-01

    This paper describes a method and apparatus for producing a porosity log of a substance formation corrected for detector stand of. It includes: lowering a logging tool having a neutron source and a neutron detector into the borehole, irradiating the subsurface formation with neutrons from the neutron source as the logging tool is traversed along the subsurface formation, recording die-away signals representing the die-away of nuclear radiation in the subsurface formation as detected by the neutron detector, producing intensity signals representing the variations in intensity of the die-away signals, producing a model of the die-away of nuclear radiation in the subsurface formation having terms varying exponentially in response to borehole, formation and background effects on the die-away of nuclear radiation as detected by the detector

  13. Logística del transporte

    OpenAIRE

    Robusté Antón, Francesc

    2005-01-01

    La logística se ha conformado como un proceso estratégico para organizar las actividades de producción y de distribución de las empresas. El concepto de sistema logístico ha incluido un amplio espectro de operaciones que condicionan la eficiencia y la competitividad empresarial en el actual contexto de globalización de la economía. En este sentido, este libro afronta y analiza los distintos aspectos que inciden en los procesos de planificación y gestión de los procesos logísticos relacionados...

  14. Nonblocking and orphan free message logging protocols

    Science.gov (United States)

    Alvisi, Lorenzo; Hoppe, Bruce; Marzullo, Keith

    1992-12-01

    Currently existing message logging protocols demonstrate a classic pessimistic vs. optimistic tradeoff. We show that the optimistic-pessimistic tradeoff is not inherent to the problem of message logging. We construct a message-logging protocol that has the positive features of both optimistic and pessimistic protocol: our protocol prevents orphans and allows simple failure recovery; however, it requires no blocking in failure-free runs. Furthermore, this protocol does not introduce any additional message overhead as compared to one implemented for a system in which messages may be lost but processes do not crash.

  15. Supply of Rubber Wood Log in Malaysia

    OpenAIRE

    Noraida, A. W.; Abdul-Rahim, A. S.

    2014-01-01

    Issue on shortage of raw material for wood processing solved by discovery of rubber wood log as one of the substitutes the natural log. This paper examines the supply of rubber wood log in Malaysia. We employ ARDL Bound Approach Test and time series data from 1980 to 2010 which represented the whole Malaysia are used to achieve the established objectives. The result shown, in the long run harvested area and wages have 1% and 10% significant level respectively. While in the short run, there wa...

  16. Plant inspection tours with mobile data logging system

    International Nuclear Information System (INIS)

    Roesser, U.

    2006-01-01

    The MDE Mobile Data Logging System has been introduced in a number of German power plants for efficient logging, evaluation, and quality-assured documentation of data recorded on plant inspection tours by means of pocket PCs instead of slips of paper. It will be installed in other nuclear power plants in the near future. The MDE system is composed of the pocket PCs for logging data during plant inspection tours, the associated docking stations installed in the respective areas of application, one PC or, if necessary, several PCs with the appropriate user software, and the associated network links. To install the software in the power plant, lists of rooms and measurement stations as well as other positions on an inspection course are transmitted to the MDE system. When the system has been commissioned, inspection tours are planned in accordance with past experience and optimized in the computer. User experience is taken into account in program updates. New functions improve user comfort and ease of evaluation. Additions to the MDE software, and applications in other areas, are tentatively planned and will be implemented as the need arises. (orig.)

  17. Drilling and logging in uranium exploration

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The report reviews drilling and logging practices in exploration of uranium ores and summarizes the papers presented in the panel meeting. Recommendations for further research and development are given

  18. Neutron logging reliability techniques and apparatus

    International Nuclear Information System (INIS)

    Johnstone, C.W.

    1975-01-01

    Apparatus and methods for verifying the validity of data derived at least in part by neutron logging of earth formations, and, where indicated, for affording neutron diffusion-corrected values of such data, are disclosed. (WHK)

  19. CMLOG: A common message logging system

    International Nuclear Information System (INIS)

    Chen, J.; Akers, W.; Bickley, M.; Wu, D.; Watson, W. III

    1997-01-01

    The Common Message Logging (CMLOG) system is an object-oriented and distributed system that not only allows applications and systems to log data (messages) of any type into a centralized database but also lets applications view incoming messages in real-time or retrieve stored data from the database according to selection rules. It consists of a concurrent Unix server that handles incoming logging or searching messages, a Motif browser that can view incoming messages in real-time or display stored data in the database, a client daemon that buffers and sends logging messages to the server, and libraries that can be used by applications to send data to or retrieve data from the database via the server. This paper presents the design and implementation of the CMLOG system meanwhile it will also address the issue of integration of CMLOG into existing control systems. CMLOG into existing control systems

  20. LATTE - Log and Time Tracking for Elections

    Data.gov (United States)

    Office of Personnel Management — LATTE - Log and Time Tracking for Elections is a time tracking and voucher preparation system used to schedule employees to cover elections, to document their time...

  1. Well Logging Equipment Updated in China

    Institute of Scientific and Technical Information of China (English)

    Xu Lili

    1996-01-01

    @@ As one of the ten principal disciplines in the petroleum industry, well logging has been developed for about 55years in China and is playing an increasingly important role in the country's oil and gas exploration and development.

  2. Conversation Threads Hidden within Email Server Logs

    Science.gov (United States)

    Palus, Sebastian; Kazienko, Przemysław

    Email server logs contain records of all email Exchange through this server. Often we would like to analyze those emails not separately but in conversation thread, especially when we need to analyze social network extracted from those email logs. Unfortunately each mail is in different record and those record are not tided to each other in any obvious way. In this paper method for discussion threads extraction was proposed together with experiments on two different data sets - Enron and WrUT..

  3. Geophysical logging of the Harwell boreholes

    International Nuclear Information System (INIS)

    Brightman, M.A.

    1983-08-01

    A comprehensive geophysical borehole logging survey was carried out on each of three deep boreholes drilled at the Harwell research site. KOALA and PETRA computer programs were used to analyse and interpret the logs to obtain continuous quantitative estimates of the geological and hydrogeological properties of the sequences penetrated at the Harwell site. Quantitative estimates of the mineral composition and porosity of the cores samples were made. (UK)

  4. Defect core detection in radiata pine logs

    International Nuclear Information System (INIS)

    Wallace, G.

    1993-01-01

    Internal defect cores in Pinus radiata logs arise primarily from the practice in New Zealand of pruning trees to increase the amount of clear wood. Realising the benefits of this practice when milling the logs is hampered by the lack of a practical method for detecting the defect cores. This report attempts to establish industry requirements for detections and examine techniques which may be suitable. Some trials of a novel technique are described. (author) 19 refs.; 11 figs

  5. Value of NMR logging for heavy oil characterization

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.; Chen, J.; Georgi, D. [Baker Hughes, Calgary, AB (Canada); Sun, B. [Chevron Energy Technology Co., Calgary, AB (Canada)

    2008-07-01

    Non-conventional, heavy oil fields are becoming increasingly important to the security of energy supplies and are becoming economically profitable to produce. Heavy oil reservoirs are difficult to evaluate since they are typically shallow and the connate waters are very fresh. Other heavy oil reservoirs are oil-wet where the resistivities are not indicative of saturation. Nuclear magnetic resonance (NMR) detects molecular level interactions. As such, it responds distinctively to different hydrocarbon molecules, thereby opening a new avenue for constituent analysis. This feature makes NMR a more powerful technique than bulk oil density or viscosity measurements for characterizing oils, and is the basis for detecting gas in heavy oil fields. NMR logging, which measures fluid in pore space directly, is capable of separating oil from water. It is possible to discern movable from bound water by analyzing NMR logs. The oil viscosity can be also quantified from NMR logs, NMR relaxation time and diffusivity estimates. The unique challenges for heavy oil reservoir characterization for the NMR technique were discussed with reference to the extra-fast decay of the NMR signal in response to extra-heavy oil/tars, and the lack of sensitivity in measuring very slow diffusion of heavy oil molecules. This paper presented various methods for analyzing heavy oil reservoirs in different viscosity ranges. Heavy oil fields in Venezuela, Kazakhstan, Canada, Alaska and the Middle East were analyzed using different data interpretation approaches based on the reservoir formation characteristics and the heavy oil type. NMR direct fluid typing was adequate for clean sands and carbonate reservoirs while integrated approaches were used to interpret extra heavy oils and tars. It was concluded that NMR logs can provide quantitative measures for heavy oil saturation, identify sweet spots or tar streaks, and quantify heavy oil viscosity within reasonable accuracy. 14 refs., 16 figs.

  6. Modeling Precipitation Extremes using Log-Histospline

    Science.gov (United States)

    Huang, W. K.; Nychka, D. W.; Zhang, H.

    2017-12-01

    One of the commonly used approaches to modeling univariate extremes is the peaks-overthreshold (POT) method. The POT method models exceedances over a (sufficiently high/low) threshold as a generalized Pareto distribution (GPD). To apply this method, a threshold has to be chosen and the estimates might be sensitive to the chosen threshold. Here we propose an alternative, the "Log-Histospline", to explore modeling the tail behavior and the remainder of the density in one step using the full range of the data. Log-Histospline applies a smoothing spline model on a finely binned histogram of the log transformed data to estimate its log density. By construction, we are able to preserve the polynomial upper tail behavior, a feature commonly observed in geophysical observations. The Log-Histospline can be extended to the spatial setting by treating the marginal (log) density at each location as spatially indexed functional data, and perform a dimension reduction and spatial smoothing. We illustrate the proposed method by analyzing precipitation data from regional climate model output (North American Regional Climate Change and Assessment Program (NARCCAP)).

  7. Increasing for effectiveness of inspection of the use of radioactive substances well logging

    International Nuclear Information System (INIS)

    Hesty Rimadianny

    2015-01-01

    One of the utilization of nuclear power is the use of radioactive substances for well logging. To ensure the achievement of radiation safety and security in the use of radioactive substances for well logging activities BAPETEN carries out inspections in accordance with the mandate as sepulated in the Government Regulation No. 29 of 2008 on the Licensing Resource Utilization Ionizing Radiation and Nuclear Materials. Besides referring to the implementation of Government Regulation inspection also refers to BAPETEN Chairman Regulation No. 5 of 2009 on Radiation Safety in the Use of Radioactive material for well logging. In 2014, of 18 facilities inspected the most significant findings include the availability of equipment safety and security of radioactive substances, as well as the availability and suitability of documents and records of safety and security of radioactive substances for well logging activities. Based on these findings BAPETEN needs to make efforts to increase the effectiveness of inspections on the use of radioactive substances for well logging. Increasing the effectiveness of these inspections include a commitment for the frequency of well logging inspection, the number of qualified of inspectors in accordance with the established procedures and optimizing the law enforcement process which includes the application of administrative sanctions in the form of a written warning, license suspension, revocation until reporting to law enforcement. Besides, BAPETEN need to improve the effectiveness of outreach programs and legal guidance as a precaution in the long run. (author)

  8. La logística integral como ventaja competitiva y sistema logístico

    Directory of Open Access Journals (Sweden)

    Mario Anselmo Martínez gallardo

    2013-07-01

    Full Text Available Esta investigación analiza la logística integral como una ventaja competitiva y el sistema logístico. Es opinión de los autores que la logística integral es esencial para el intercambio de mercancías, toda vez que reduce costos y hace más ágil la actividad comercial. La utilización de esta logística representa una ventaja competitiva con respecto de otras empresas por la optimización del capital y ahorro de tiempo.

  9. Well logging with natural gamma radiation

    International Nuclear Information System (INIS)

    Ellis, D.V.

    1983-01-01

    An invention is described for use in natural gamma radiation well logging in which measurements taken in a borehole are used in the search for valuable underground resources such as oil or gas. The invention comprises deriving a log of natural gamma radiation detected in selected energy windows for a selected borehole depth interval and converting it into a log of the selected subsurface materials, e.g. Th, U, K. This log is corrected for the effects of 1) either a gamma ray emitter in the borehole fluid, e.g. potassium salts and/or 2) a gamma ray attenuator in the borehole fluid, e.g. a strong attenuator such as barite and/or hematite. The Th, U, K log is particularly useful in the exploration of oil and gas resources since the Th, U, K concentrations are a good indication as to the presence, type and volume of shale and clay in the formations surrounding the borehole. (U.K.)

  10. AML (Advanced Mud Logging: First Among Equals

    Directory of Open Access Journals (Sweden)

    T. Loermans

    2017-09-01

    Full Text Available During the past ten years an enormous development in mud logging technology has been made. Traditional mud logging was only qualitative in nature, and mudlogs could not be used for the petrophysical well evaluations which form the basis for all subsequent activities on wells and fields. AML however can provide quantitative information, logs with a reliability, trueness and precision like LWD and WLL. Hence for well evaluation programmes there are now three different logging methods available, each with its own pros and cons on specific aspects: AML, LWD and WLL. The largest improvements have been made in mud gas analysis and elemental analysis of cuttings. Mud gas analysis can yield hydrocarbon fluid composition for some components with a quality like PVT analysis, hence not only revolutionising the sampling programme so far done with only LWD/WLL, but also making it possible to geosteer on fluid properties. Elemental analysis of cuttings, e.g. with XRF, with an ability well beyond the capabilities of the spectroscopy measurements possible earlier with LWD/WLL tools, is opening up improved ways to evaluate formations, especially of course where the traditional methods are falling short of requirements, such as in unconventional reservoirs. An overview and specific examples of these AML logs is given, from which it may be concluded that AML now ought to be considered as “first among its equals”.

  11. Applications of nuclear physics

    Science.gov (United States)

    Hayes, A. C.

    2017-02-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

  12. Applications of nuclear physics

    International Nuclear Information System (INIS)

    Hayes-Sterbenz, Anna Catherine

    2017-01-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Lastly, each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

  13. Proposal for regulation of logging activities in oil wells using ionizing radiation sources

    International Nuclear Information System (INIS)

    Hidrowoh, Jacob R.

    2000-01-01

    It covers general aspects of nuclear energy and the suitable legal frame for its application related to oil industry. Besides, a regulation proposal to control logging activities in Ecuador using ionizing radiation sources in oil wells. It was prepared taking into account the Ecuadorian Atomic Energy Commission criteria and international regulations

  14. Pulsed neutron logging - a modern approach to petroleum exploration

    International Nuclear Information System (INIS)

    Navalkar, M.P.

    1978-01-01

    As hydrocarbons have strikingly different properties for neutrons as compared with rocks, neutronic methods are useful to prepare logs of bore holes drilled for petroleum exploration. The earlier neutron logs were based on steady neutron sources, but the superior logs, namely, neutron life time log and neutron induced spectral log are based on pulsed neutron sources. The methods of obtaining these logs, their limitations and the field equipment required are described briefly. As the two logs are complementary, a plea has been made to develop field equipment which can obtain two logs in a single run. (M.G.B.)

  15. Fracture diagnostics with tube wave reflection logs

    International Nuclear Information System (INIS)

    Medlin, W.L.

    1991-01-01

    This paper reports on the Tube Wave Reflection Log (TWRL) which is acoustic logging method which provides information about the height, location and conductivity of hydraulically induced fractures behind perforated casing. The TWRL tool consists of a transmitter and closely spaced receiver. The transmitter is driven with a short, low frequency tone burst to generate long wavelength tube waves which are little attenuated in unperforated casing. They are partially reflected when they pass perforated intervals communicating with a hydraulically induced fracture. The tool listens for such reflections for 0.1 seconds following each excitation burst. As the tool is moved uphole at logging speed, the transmitter is excited at each foot of depth. VDL displays of the TWRL records provide reflection traces whose projections define the uppermost and lower-most perforations communicating with the fracture. The strength of the reflections depends on the ease of fluid flow into the fracture and thus, is an indicator of fracture conductivity

  16. Smartphone log data in a qualitative perspective

    DEFF Research Database (Denmark)

    Ørmen, Jacob; Thorhauge, Anne Mette

    2015-01-01

    into studies of smartphones in everyday life. Through an illustrative study, we explore a more nuanced perspective on what can be considered “log data” and how these types of data can be collected and analysed. A qualitative approach to log data analysis offers researchers new opportunities to situate......Log data from smartphones have primarily been used in large-scale research designs to draw statistical inferences from hundreds or even thousands of participants. In this article, we argue that more qualitatively oriented designs can also benefit greatly from integrating these rich data sources...... serve as cues to instigate discussion and reflection as well as act as resources for contextualizing and organizing related empirical material. In the discussion, the advantages of a qualitative perspective for research designs are assessed in relation to issues of validity. Further perspectives...

  17. Financial feasibility of a log sort yard handling small-diameter logs: A preliminary study

    Science.gov (United States)

    Han-Sup Han; E. M. (Ted) Bilek; John (Rusty) Dramm; Dan Loeffler; Dave Calkin

    2011-01-01

    The value and use of the trees removed in fuel reduction thinning and restoration treatments could be enhanced if the wood were effectively evaluated and sorted for quality and highest value before delivery to the next manufacturing destination. This article summarizes a preliminary financial feasibility analysis of a log sort yard that would serve as a log market to...

  18. Geothermal well log interpretation midterm report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1979-02-01

    Reservoir types are defined according to fluid phase and temperature, lithology, geologic province, pore geometry, and salinity and fluid chemistry. Improvements are needed in lithology and porosity definition, fracture detection, and thermal evaluation for more accurate interpretation. Further efforts are directed toward improving diagnostic techniques for relating rock characteristics and log response, developing petrophysical models for geothermal systems, and developing thermal evaluation techniques. The Geothermal Well Log Interpretation study and report has concentrated only on hydrothermal geothermal reservoirs. Other geothermal reservoirs (hot dry rock, geopressured, etc.) are not considered.

  19. New portable neutron generator for well logging

    International Nuclear Information System (INIS)

    Chicanov, A.E.; Gromov, E. V.; Gulko, V. M.; Izmailov, A. V.

    1994-01-01

    The information about the design, investigation and testing of new well neutron generator for the pulse neutron logging (PNL) is given in this paper. The main physical characteristics of new PNL apparatus are: Neutron flux 2.10 sup 8 n/s ; Pulse frequency>=400 Hz; Diameter= 90 mm; Logging velocity >200 m/h; Number of probes = 2; Resource > 300 h. The generator were provided by gas-filled neutron accelerative tube named NTF-2. The perspective of application and optimization shown PNL apparatus are considered. (author)

  20. Analyzing Log Files using Data-Mining

    Directory of Open Access Journals (Sweden)

    Marius Mihut

    2008-01-01

    Full Text Available Information systems (i.e. servers, applications and communication devices create a large amount of monitoring data that are saved as log files. For analyzing them, a data-mining approach is helpful. This article presents the steps which are necessary for creating an ‘analyzing instrument’, based on an open source software called Waikato Environment for Knowledge Analysis (Weka [1]. For exemplification, a system log file created by a Windows-based operating system, is used as input file.

  1. Kaizen aplicado à logística

    OpenAIRE

    Santos, Ana Catarina Almeida

    2011-01-01

    O presente trabalho propõe alcançar um aumento de produtividade e consequente redução de custos e desperdícios ajudando o departamento logístico da Empresa Revigrés – Industria de Revestimentos de Grés, Lda, a tornar-se mais eficiente, através da aplicação da filosofia kaizen que propõe melhorias no desempenho por implementação de pequenas ações. O objetivo deste projeto é a melhoria do departamento logístico globalmente, para isso houve o recurso a pesquisas e levantamento ...

  2. Geophysical borehole logging test procedure: Final draft

    International Nuclear Information System (INIS)

    1986-09-01

    The purpose of geophysical borehole logging from the At-Depth Facility (ADF) is to provide information which will assist in characterizing the site geologic conditions and in classifying the engineering characteristics of the rock mass in the vicinity of the ADF. The direct goals of borehole logging include identification of lithologic units and their correlation from hole to hole, identification of fractured or otherwise porous or permeable zones, quantitative or semi-quantitative estimation of various formation properties, and evaluation of factors such as the borehole diameter and orientation. 11 figs., 4 tabs

  3. CS model coil experimental log book

    International Nuclear Information System (INIS)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  4. Perfil logístico de Colombia

    OpenAIRE

    Cardozo Maglioni, María Victoria; Lozano Suarez, María Goretty

    2012-01-01

    El presente documento ofrece un estudio del perfil logístico de Colombia con la finalidad de dar a conocer el estado de arte de las ciudades, puertos e infraestructura principal para facilitar la toma de decisiones de los empresarios. Para el desarrollo de este trabajo se determinaron a partir de un análisis competitivo del país; las principales ciudades y puertos; logrando establecer un inventario de maquinaria y equipo e infraestructura logística; enmarcados en retos ya establecidos en las ...

  5. Well logging instrumental and methodological research

    International Nuclear Information System (INIS)

    Andrassy, L.; Barath, I.; Dorko, R.

    1983-01-01

    This part of the Annual Report of the Roland Eoetvoes Geophysical Institute (ELGI) of Hungary for 1982, summarizes the well logging instrumental and methodological researches of ELGI. The theoretical neutron diffusion fluxes for black and brown coals of Hungarian mines were calculated. A coal probe was developed and tested in boreholes using computerized data processing and interpretation. An X-ray radiometric method was used for the determination of Cu and Fe contents of minerals. Researches in the field of magnetic susceptibility and induced polarization logging are also summarized. A rapid analyzer for bauxite mining and a photorecorder for petroleum industry were developed by ELGI. (D.Gy.)

  6. Extracting useful knowledge from event logs

    DEFF Research Database (Denmark)

    Djenouri, Youcef; Belhadi, Asma; Fournier-Viger, Philippe

    2018-01-01

    Business process analysis is a key activity that aims at increasing the efficiency of business operations. In recent years, several data mining based methods have been designed for discovering interesting patterns in event logs. A popular type of methods consists of applying frequent itemset mini...

  7. Potential for shared log transport services

    Science.gov (United States)

    Tim McDonald; Steve Taylor; Jorge Valenzuela

    2001-01-01

    A simulation model of a log transport logistics network was developed. The model could be structured to either share truck capacity among a group of loggers, or to assign a fixed number of trucks to individual loggers. Another variation of the model allowed the use of a staging yard to set out loaded trailers and deliver them to destinations using dedicated shuttle...

  8. Identifying unstable sites on logging roads

    Science.gov (United States)

    R. M. Rice; J. Lewis

    1986-01-01

    Logging roads are an important source of forestry-related erosion. The amount of erosion on a forest road is determined by the interaction between how the road is constructed and maintained and the environment in which it is built. The roads in this study were constructed with large bulldozers, and most excavated material was sidecast. The roads studied were...

  9. Narrating Illegal Logging Across the Globe

    DEFF Research Database (Denmark)

    Winkel, Georg; Leipold, Sina; Buhmann, Karin

    2017-01-01

    In the last decade illegal logging has triggered the attention of policy makers and scholars of international forest governance. The issue is multifaceted, involving aspects of social and environmental sustainability, development, trade, access to markets and competitiveness. A vivid academic deb...

  10. Modelling tropical forests response to logging

    Science.gov (United States)

    Cazzolla Gatti, Roberto; Di Paola, Arianna; Valentini, Riccardo; Paparella, Francesco

    2013-04-01

    Tropical rainforests are among the most threatened ecosystems by large-scale fragmentation due to human activity such as heavy logging and agricultural clearance. Although, they provide crucial ecosystem goods and services, such as sequestering carbon from the atmosphere, protecting watersheds and conserving biodiversity. In several countries forest resource extraction has experienced a shift from clearcutting to selective logging to maintain a significant forest cover and understock of living biomass. However the knowledge on the short and long-term effects of removing selected species in tropical rainforest are scarce and need to be further investigated. One of the main effects of selective logging on forest dynamics seems to be the local disturbance which involve the invasion of open space by weed, vines and climbers at the expense of the late-successional state cenosis. We present a simple deterministic model that describes the dynamics of tropical rainforest subject to selective logging to understand how and why weeds displace native species. We argue that the selective removal of tallest tropical trees carries out gaps of light that allow weeds, vines and climbers to prevail on native species, inhibiting the possibility of recovery of the original vegetation. Our results show that different regime shifts may occur depending on the type of forest management adopted. This hypothesis is supported by a dataset of trees height and weed/vines cover that we collected from 9 plots located in Central and West Africa both in untouched and managed areas.

  11. ADN* Density log estimation Using Rockcell*

    International Nuclear Information System (INIS)

    Okuku, C.; Iloghalu, Emeka. M.; Omotayo, O.

    2003-01-01

    This work is intended to inform on the possibilities of estimating good density data in zones associated with sliding in a reservoir with ADN* tool with or without ADOS in string in cases where repeat sections were not done, possibly due to hole stability or directional concerns. This procedure has been equally used to obtain a better density data in corkscrew holes. Density data (ROBB) was recomputed using neural network in RockCell* to estimate the density over zones of interest. RockCell* is a Schlumberger software that has neural network functionally which can be used to estimate missing logs using the combination of the responses of other log curves and intervals that are not affected by sliding. In this work, an interval was selected and within this interval twelve litho zones were defined using the unsupervised neural network. From this a training set was selected based on intervals of very good log responses outside the sliding zones. This training set was used to train and run the neural network for a specific lithostratigraphic interval. The results matched the known good density curve. Then after this, an estimation of the density curve was done using the supervised neural network. The output from this estimation matched very closely in the good portions of the log, thus providing some density measurements in the sliding zone. This methodology provides a scientific solution to missing data during the process of Formation evaluation

  12. Changes in the Logging Labor Force

    Science.gov (United States)

    Charles H. Wolf; Jean W. Nolley

    1977-01-01

    Employment in the logging industry dropped 28 percent between 1950 and 1970, while output of industrial roundwood increased 31 percent. Today's loggers are older, better educated, and more skilled. A large proportion are self-employed, many work less than a full year, and a substantial number have incomes below the poverty level. Mechanization of timber harvesting...

  13. Alaska midgrade logs: supply and offshore demand.

    Science.gov (United States)

    Donald F. Flora; Wendy J. McGinnis

    1989-01-01

    The outlook for shipments and prices of export logs from Alaska differs significantly by grade (quality class). For the majority lying in the middle of the value range, the trend of prices is projected to increase $200 per thousand board feet, or about 55 percent, by 2000. Shipments are expected to rise about 30 percent by 1995 and then subside about 10 percent. These...

  14. Analyzing Grid Log Data with Affinity Propagation

    NARCIS (Netherlands)

    Modena, G.; van Someren, M.W.; Ali, M; Bosse, T.; Hindriks, K.V.; Hoogendoorn, M.; Jonker, C.M; Treur, J.

    2013-01-01

    In this paper we present an unsupervised learning approach to detect meaningful job traffic patterns in Grid log data. Manual anomaly detection on modern Grid environments is troublesome given their increasing complexity, the distributed, dynamic topology of the network and heterogeneity of the jobs

  15. Exploration and grade control neutron logging

    International Nuclear Information System (INIS)

    Eisler, P.L.

    1982-01-01

    Techniques used in neutron logging in boreholes are discussed. They include the application of neutron probes to porosity measurements, to lithological determinations based on macroscopic cross-section measurements and measurements of the concentration of chemical constituents in rocks and ores

  16. Explorations in statistics: the log transformation.

    Science.gov (United States)

    Curran-Everett, Douglas

    2018-06-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This thirteenth installment of Explorations in Statistics explores the log transformation, an established technique that rescales the actual observations from an experiment so that the assumptions of some statistical analysis are better met. A general assumption in statistics is that the variability of some response Y is homogeneous across groups or across some predictor variable X. If the variability-the standard deviation-varies in rough proportion to the mean value of Y, a log transformation can equalize the standard deviations. Moreover, if the actual observations from an experiment conform to a skewed distribution, then a log transformation can make the theoretical distribution of the sample mean more consistent with a normal distribution. This is important: the results of a one-sample t test are meaningful only if the theoretical distribution of the sample mean is roughly normal. If we log-transform our observations, then we want to confirm the transformation was useful. We can do this if we use the Box-Cox method, if we bootstrap the sample mean and the statistic t itself, and if we assess the residual plots from the statistical model of the actual and transformed sample observations.

  17. Apache Flume distributed log collection for Hadoop

    CERN Document Server

    D'Souza, Subas

    2013-01-01

    A starter guide that covers Apache Flume in detail.Apache Flume: Distributed Log Collection for Hadoop is intended for people who are responsible for moving datasets into Hadoop in a timely and reliable manner like software engineers, database administrators, and data warehouse administrators

  18. 47 CFR 80.409 - Station logs.

    Science.gov (United States)

    2010-10-01

    ... primary office or available to the Commission via secured access to the licensee's Internet web site. Logs..., together with the time of such observation or occurrence and the position of the ship or other mobile unit... devices which do not have integral navigation receivers, including: VHF DSC, MF DSC, satellite EPIRB and...

  19. Geophysical logging for mineral exploration and development

    International Nuclear Information System (INIS)

    Plouffe, R.D.

    1981-01-01

    It is possible to retrieve from small-diameter holes geophysical data for qualitative interpretation in exploration and quantitative interpretation in the development of orebodies. The primary objectives in the exploration stage are to identify where, within a hole, economic minerals are, and to help in lithological interpretations. Other aspects, which are more quantitative, are the interpretation of downhole logs for parameters which can be used in surface geophysical methods (i.e. density for gravity surveys, acoustic velocities for seismic surveys, and magnetic susceptibility for airborne and ground magnetic surveys). Recent advances in equipment design, portability and durability have made downhole logging in exploration more inexpensive and reliable. This new equipment is being used to generate very precise quantitative results. This is especially true on uranium development projects. The interpretation of gamma logs for eU 3 O 8 values has finally become precise enough that they have begun to replace chemical values in reserve calculations. Another part of development data is density and equilibrium information, which, with today's technology, is being derived from downhole probing. In the years to come, the trends for many metals are toward neutron activation techniques, or in-situ assaying, and the use of multiple logs for better lithological and physical rock property determinations. (auth)

  20. Information needs for increasing log transport efficiency

    Science.gov (United States)

    Timothy P. McDonald; Steven E. Taylor; Robert B. Rummer; Jorge Valenzuela

    2001-01-01

    Three methods of dispatching trucks to loggers were tested using a log transport simulation model: random allocation, fixed assignment of trucks to loggers, and dispatch based on knowledge of the current status of trucks and loggers within the system. This 'informed' dispatch algorithm attempted to minimize the difference in time between when a logger would...

  1. Root cause analysis with enriched process logs

    NARCIS (Netherlands)

    Suriadi, S.; Ouyang, C.; Aalst, van der W.M.P.; Hofstede, ter A.H.M.; La Rosa, M.; Soffer, P.

    2013-01-01

    n the field of process mining, the use of event logs for the purpose of root cause analysis is increasingly studied. In such an analysis, the availability of attributes/features that may explain the root cause of some phenomena is crucial. Currently, the process of obtaining these attributes from

  2. Mining process performance from event logs

    NARCIS (Netherlands)

    Adriansyah, A.; Buijs, J.C.A.M.; La Rosa, M.; Soffer, P.

    2013-01-01

    In systems where process executions are not strictly enforced by a predefined process model, obtaining reliable performance information is not trivial. In this paper, we analyzed an event log of a real-life process, taken from a Dutch financial institute, using process mining techniques. In

  3. Lianas and logging in West Africa

    NARCIS (Netherlands)

    Parren, M.P.E.

    2003-01-01

    The role of lianas in relation to logging activities is analysed in a lowland moist forest in Cameroon. Lianas are an abundant, diverse, and conspicuous growth form in nearly all tropical forests. Lianas are mostly seen as a nuisance by foresters. Cutting of liana stems is an important operation in

  4. Requirements-Driven Log Analysis Extended Abstract

    Science.gov (United States)

    Havelund, Klaus

    2012-01-01

    Imagine that you are tasked to help a project improve their testing effort. In a realistic scenario it will quickly become clear, that having an impact is diffcult. First of all, it will likely be a challenge to suggest an alternative approach which is significantly more automated and/or more effective than current practice. The reality is that an average software system has a complex input/output behavior. An automated testing approach will have to auto-generate test cases, each being a pair (i; o) consisting of a test input i and an oracle o. The test input i has to be somewhat meaningful, and the oracle o can be very complicated to compute. Second, even in case where some testing technology has been developed that might improve current practice, it is then likely difficult to completely change the current behavior of the testing team unless the technique is obviously superior and does everything already done by existing technology. So is there an easier way to incorporate formal methods-based approaches than the full edged test revolution? Fortunately the answer is affirmative. A relatively simple approach is to benefit from possibly already existing logging infrastructure, which after all is part of most systems put in production. A log is a sequence of events, generated by special log recording statements, most often manually inserted in the code by the programmers. An event can be considered as a data record: a mapping from field names to values. We can analyze such a log using formal methods, for example checking it against a formal specification. This separates running the system for analyzing its behavior. It is not meant as an alternative to testing since it does not address the important in- put generation problem. However, it offers a solution which testing teams might accept since it has low impact on the existing process. A single person might be assigned to perform such log analysis, compared to the entire testing team changing behavior.

  5. Anomalous self potential (sp) log signatures observed in a water ...

    African Journals Online (AJOL)

    Geophysical logging was done after drilling had been completed in a water well at Okwudor, South Eastern Nigeria. Three electric logs were run viz: Self Potential (SP), Resistivity N16″ and N64″ logs. An anomaly was observed in the SP log. The SP results from this well show some deviation from the standard norm.

  6. Using Web Server Logs in Evaluating Instructional Web Sites.

    Science.gov (United States)

    Ingram, Albert L.

    2000-01-01

    Web server logs contain a great deal of information about who uses a Web site and how they use it. This article discusses the analysis of Web logs for instructional Web sites; reviews the data stored in most Web server logs; demonstrates what further information can be gleaned from the logs; and discusses analyzing that information for the…

  7. Stress wave sorting of red maple logs for structural quality

    Science.gov (United States)

    Xiping Wang; Robert J. Ross; David W. Green; Brian Brashaw; Karl Englund; Michael Wolcott

    2004-01-01

    Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) of logs. It is questionable whether the visual grading procedures currently used for logs adequately assess the potential quality of structural products manufactured from them, especially...

  8. Tradeoffs and interdependence in the Alaska cant and log markets.

    Science.gov (United States)

    Donald Flora; Una Woller; Michael. Neergaard

    1990-01-01

    During the 1980s, log exports from Alaska have risen while cant (lumber) exports have declined. Eight explanations for the difference between cant and log market behavior are explored. It seems that declining demand for wood products in Japan and a surge of private-sector log harvests in Alaska are enough to account for the apparent substitution of logs for cants. It...

  9. Performance of sampling methods to estimate log characteristics for wildlife.

    Science.gov (United States)

    Lisa J. Bate; Torolf R. Torgersen; Michael J. Wisdom; Edward O. Garton

    2004-01-01

    Accurate estimation of the characteristics of log resources, or coarse woody debris (CWD), is critical to effective management of wildlife and other forest resources. Despite the importance of logs as wildlife habitat, methods for sampling logs have traditionally focused on silvicultural and fire applications. These applications have emphasized estimates of log volume...

  10. Advanced of X-ray fluorescence logging technique in China

    International Nuclear Information System (INIS)

    Zhou Sichun; Ge Liangquan; Lai Wanchang; Yang Qiang

    2010-01-01

    The paper discuses principle of X-ray fluorescence logging, and introduces advanced of X-ray fluorescence logging technique in China. By 2009, third generation XRF logging instrument has been developed in China, and good logging result has been obtained in Lala copper mine. (authors)

  11. Logging utilization in Idaho: Current and past trends

    Science.gov (United States)

    Eric A. Simmons; Todd A. Morgan; Erik C. Berg; Stanley J. Zarnoch; Steven W. Hayes; Mike T. Thompson

    2014-01-01

    A study of commercial timber-harvesting activities in Idaho was conducted during 2008 and 2011 to characterize current tree utilization, logging operations, and changes from previous Idaho logging utilization studies. A two-stage simple random sampling design was used to select sites and felled trees for measurement within active logging sites. Thirty-three logging...

  12. Limitations and developing directions of pulsed neutron logging

    International Nuclear Information System (INIS)

    Wu Wensheng; Xiao Lizhi

    2007-01-01

    The paper explains briefly the principle of pulsed neutron logging method, summarizes the system and uses of the method in petroleum logging. The paper points out the limitations of pulsed neutron logging such as low precise measurements, low logging speed, plenty of influence factors, low vertical resolution, bad adaptability, difficult logging interpretation and so on, and expounds its developing directions in hardware, software, method and principle. (authors)

  13. Theoretical and Numerical Study of Seismoelectric Logs for Logging While Drilling (LWD

    Directory of Open Access Journals (Sweden)

    Sun Xiang-Yang

    2017-01-01

    Full Text Available When the acoustic field propagates in the porous medium, the electromagnetic wave can be induced by the seismoelectric effects which can be used in the logging. This paper studies the seismoelectric wave field and deduces the formulations of the acoustic and electromagnetic field of the liquid in the well, and gives the acoustic and electromagnetic boundary conditions between the driller collar and the log liquid, when the driller collar is added. We also do the numerical simulation of the seismoelectric wave field excited by monopole source, study the velocity dispersion characteristics of the acoustic and electromagnetic field, and investigate the detective depth of the seismoelectric logs. Through the simulation we know the seismoelectric logs can avoid the interference of drill collar wave. This paper also provides theoretical guidance for the design of receiving antenna.

  14. CS model coil experimental log book

    Energy Technology Data Exchange (ETDEWEB)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  15. High resolution gamma spectroscopy well logging system

    International Nuclear Information System (INIS)

    Giles, J.R.; Dooley, K.J.

    1997-01-01

    A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. The absolute counting efficiencies of the GSLS detectors were determined using cylindrical reference sources. More complex borehole geometries were modeled using commercially available shielding software and correction factors were developed based on relative gamma-ray fluence rates. Examination of varying porosity and moisture content showed that as porosity increases, and as the formation saturation ratio decreases, relative gamma-ray fluence rates increase linearly for all energies. Correction factors for iron and water cylindrical shields were found to agree well with correction factors determined during previous studies allowing for the development of correction factors for type-304 stainless steel and low-carbon steel casings. Regression analyses of correction factor data produced equations for determining correction factors applicable to spectral gamma-ray well logs acquired under non-standard borehole conditions

  16. Assessment of radiation safety in well logging

    International Nuclear Information System (INIS)

    Alles, A.; Pérez, Y.; Duménigo, C.

    2015-01-01

    Radiation safety assessments required by current regulations are a means to verify compliance with the requirements. Different methods have been used for this purpose. In the paper the results of applying the method of risk matrices, applied for the first time in the practice of well logging are exposed. For each initiating event frequency of occurrence, the severity of its consequences and the probability of failure of the barriers identified were evaluated. Starting from these assumptions, the risk associated is determined for each of the identified accident sequences, using for this the SEVRRA code 'Risk Assessment System', originally designed for use in radiotherapy. As an result sequences increased risk associated with the practice of well logging were identified, which is the starting point for the further implementation of a coherent program of dose optimization in practice. [es

  17. No chiral truncation of quantum log gravity?

    Science.gov (United States)

    Andrade, Tomás; Marolf, Donald

    2010-03-01

    At the classical level, chiral gravity may be constructed as a consistent truncation of a larger theory called log gravity by requiring that left-moving charges vanish. In turn, log gravity is the limit of topologically massive gravity (TMG) at a special value of the coupling (the chiral point). We study the situation at the level of linearized quantum fields, focussing on a unitary quantization. While the TMG Hilbert space is continuous at the chiral point, the left-moving Virasoro generators become ill-defined and cannot be used to define a chiral truncation. In a sense, the left-moving asymptotic symmetries are spontaneously broken at the chiral point. In contrast, in a non-unitary quantization of TMG, both the Hilbert space and charges are continuous at the chiral point and define a unitary theory of chiral gravity at the linearized level.

  18. Modelo de custos logísticos

    Directory of Open Access Journals (Sweden)

    José Vanderlei Silva Borba

    2010-05-01

    Full Text Available Em contexto de globalização, a distância física entre produtores de bens e de serviços e consumidores deixa de ser relevante. Isso determina que o gerenciamento de custos logísticos venha agregar valor relevante aos produtos comercializados, pois procura identificar e determinar a eficácia dos recursos consumidos internamente pela empresa e, externamente, procura fazer a análise da cadeia de valor. Nessa perspectiva, a definição das variáveis de custos está além de seus muros. Este trabalho propõe um modelo de apuração de custos logísticos, que atenda, simultaneamente, os custos de suprimentos e os custos de distribuição, com impactos sobre o processo de tomada de decisão.

  19. Development of a digital log ratemeter

    International Nuclear Information System (INIS)

    Domienikan, Claudio; Brito, Andreia; Toledo, Fabio de; Zahn, Guilherme S.

    2011-01-01

    A compact log ratemeter that measures and displays an average count rate through a microcomputer is presented. This ratemeter was developed to be used to monitor a laboratory of production of radioactive samples and also for teaching purposes. The main features are log measurement range from .1 to 1.000 counts/sec and adjustable level alarm. The electronic circuit uses a Geiger tube LND7224, and the processed signal is applied to a National Instruments Multifunction I/O USB-6008 connected to a PC through USB input. A program developed in LabView allows storage of data and real-time observation of the rate of radiation evolution. This ratemeter was designed and constructed in the IPEN-CNEN/SP. (author)

  20. Glass scintillator pair for compensation neutron logging

    International Nuclear Information System (INIS)

    Ji Changsong; Li Xuezhi; Yiu Guangduo

    1985-01-01

    Glass scintillator pair types ST 1604 and ST 1605 for compensation of neutron logging is developed. The neutron sensitive material used is multistick lithium glass scintillators 3 and 4 mm in diameter respectively. Thermoneutron detection efficiencies are 50-60% and 100% respectively. The detection efficiency for 60 Co γ ray is lower than 0.3%. The type ST 1604 and ST 1605 may also be used as high sensitive neutron detectors in an intensive γ ray field

  1. Log Gaussian Cox processes on the sphere

    DEFF Research Database (Denmark)

    Pacheco, Francisco Andrés Cuevas; Møller, Jesper

    We define and study the existence of log Gaussian Cox processes (LGCPs) for the description of inhomogeneous and aggregated/clustered point patterns on the d-dimensional sphere, with d = 2 of primary interest. Useful theoretical properties of LGCPs are studied and applied for the description of sky...... positions of galaxies, in comparison with previous analysis using a Thomas process. We focus on simple estimation procedures and model checking based on functional summary statistics and the global envelope test....

  2. Log-Concavity Properties of Minkowski Valuations

    OpenAIRE

    Berg, Astrid; Parapatits, Lukas; Schuster, Franz E.; Weberndorfer, Manuel

    2014-01-01

    New Orlicz Brunn-Minkowski inequalities are established for rigid motion compatible Minkowski valuations of arbitrary degree. These extend classical log-concavity properties of intrinsic volumes and generalize seminal results of Lutwak and others. Two different approaches which refine previously employed techniques are explored. It is shown that both lead to the same class of Minkowski valuations for which these inequalities hold. An appendix by Semyon Alesker contains the proof of a new clas...

  3. Methods for calibrating radioactivity well logging tools

    International Nuclear Information System (INIS)

    Waggoner, J.A.; Turcotte, R.E.; Hunt-Grubbe, R.H.

    1981-01-01

    Field-calibrating of well-logging tools is achieved by means of a sleeve, which has radioactive material distributed therein, and which envelopes the portion of the tool housing containing the detector. Accurate calibration can be performed and the source can be made considerably weaker than those now in use as it can be brought very close to the detector thus lessening errors. (U.K.)

  4. SDSS Log Viewer: visual exploratory analysis of large-volume SQL log data

    Science.gov (United States)

    Zhang, Jian; Chen, Chaomei; Vogeley, Michael S.; Pan, Danny; Thakar, Ani; Raddick, Jordan

    2012-01-01

    User-generated Structured Query Language (SQL) queries are a rich source of information for database analysts, information scientists, and the end users of databases. In this study a group of scientists in astronomy and computer and information scientists work together to analyze a large volume of SQL log data generated by users of the Sloan Digital Sky Survey (SDSS) data archive in order to better understand users' data seeking behavior. While statistical analysis of such logs is useful at aggregated levels, efficiently exploring specific patterns of queries is often a challenging task due to the typically large volume of the data, multivariate features, and data requirements specified in SQL queries. To enable and facilitate effective and efficient exploration of the SDSS log data, we designed an interactive visualization tool, called the SDSS Log Viewer, which integrates time series visualization, text visualization, and dynamic query techniques. We describe two analysis scenarios of visual exploration of SDSS log data, including understanding unusually high daily query traffic and modeling the types of data seeking behaviors of massive query generators. The two scenarios demonstrate that the SDSS Log Viewer provides a novel and potentially valuable approach to support these targeted tasks.

  5. Estimation of the non records logs from existing logs using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Mehdi Mohammad Salehi

    2017-12-01

    Full Text Available Finding the information of the hydrocarbon reservoirs from well logs is one of the main objectives of the engineers. But, missing the log records (due to many reasons such as broken instruments, unsuitable borehole and etc. is a major challenge to achieve it. Prediction of the density and resistivity logs (Rt, DT and LLS from the conventional wire-line logs in one of the Iranian southwest oil fields is the main purpose of this study. Multilayer neural network was applied to develop an intelligent predictive model for prediction of the logs. A total of 3000 data sets from 3 wells (A, B and C of the studied field were used. Among them, the data of A, B and C wells were used to constructing and testing the model, respectively. To evaluate the performance of the model, the mean square error (MSE and correlation coefficient (R2 in the test data were calculated. A comparison between the MSE of the proposed model and recently intelligent models shows that the proposed model is more accurate than others. Acceptable accuracy and using conventional well logging data are the highlight advantages of the proposed intelligent model.

  6. Chiral gravity, log gravity, and extremal CFT

    International Nuclear Information System (INIS)

    Maloney, Alexander; Song Wei; Strominger, Andrew

    2010-01-01

    We show that the linearization of all exact solutions of classical chiral gravity around the AdS 3 vacuum have positive energy. Nonchiral and negative-energy solutions of the linearized equations are infrared divergent at second order, and so are removed from the spectrum. In other words, chirality is confined and the equations of motion have linearization instabilities. We prove that the only stationary, axially symmetric solutions of chiral gravity are BTZ black holes, which have positive energy. It is further shown that classical log gravity--the theory with logarithmically relaxed boundary conditions--has finite asymptotic symmetry generators but is not chiral and hence may be dual at the quantum level to a logarithmic conformal field theories (CFT). Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We formally evaluate the Euclidean sum over geometries of chiral gravity and show that it gives precisely the holomorphic extremal CFT partition function. The modular invariance and integrality of the expansion coefficients of this partition function are consistent with the existence of an exact quantum theory of chiral gravity. We argue that the problem of quantizing chiral gravity is the holographic dual of the problem of constructing an extremal CFT, while quantizing log gravity is dual to the problem of constructing a logarithmic extremal CFT.

  7. Gerencia logística y global

    Directory of Open Access Journals (Sweden)

    Pablo Cesar Ocampo Vélez

    2009-04-01

    Full Text Available La logística es una filosofía que se encarga de aplicar las buenas pá¡cticas en los macroprocesos, procesos, procedimientos, tareas y productos dentro de una organización, con el fin de satisfacer las necesidades del cliente, quien es la razón de ser de la empresa. Existen entes internacionales que velan porque las compañias en todo el mundo utilicen y difundan las diferentes disciplinas logísticas en toda la red de valor y tengan un mismo enfoque estratégico.El objetivo de este artículo es explicar la existencia de procesos y macroprocesos de clase mundial en la logística, gracias a los cuales hay una gran oportunidad de mejora para los empresarios colombianos, con el fin de reestructurar los procesos estratégicos, tácticos y operacionales de cada Unidad de Negocio, para que sean organizaciones más competitivas, que puedan enfrentar los tratados de libre comercio, brindando mayor sostenibilidad y óptimo nivel de servicio.

  8. Analysis of geophysical well logs from the Mariano Lake-Lake Valley drilling project, San Juan Basin, Northwestern New Mexico

    International Nuclear Information System (INIS)

    Scott, J.H.

    1986-01-01

    Geophysical well logs were obtained in eight deep holes drilled and cored by the U.S. Geological Survey to examine the geology of the Mariano Lake-Lake Valley area in the southern part of the San Juan basin, New Mexico. The logs were made to determine the petrophysical properties of the rocks penetrated by the holes, to aid in making stratigraphic correlations between the holes, and to estimate the grade of uranium enrichment in mineralized zones. The logs can be divided into six categories-nuclear, electric, sonic, magnetic, dipmeter, and borehole conditions. Examples of these logs are presented and related to lithological and petrophysical properties of the cores recovered. Gamma-ray and prompt fission neutron logs were used to estimate uranium grade in mineralized zones. Resistivity and spontaneous potential logs were used to make stratigraphic correlations between drill holes and to determine the variability of the sandstone:mudstone ratios of the major sedimentary units. In one drill hole a dipmeter log was used to estimate the direction of sediment transport of the fluvial host rock. Magnetic susceptibility logs provided supportive information for a laboratory study of magnetic mineral alteration in drill cores. This study was used to infer the geochemical and hydrologic environment associated with uranium deposition in the project area

  9. Estimating pore-space gas hydrate saturations from well log acoustic data

    Science.gov (United States)

    Lee, Myung W.; Waite, William F.

    2008-07-01

    Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate-bearing sands are modeled using a three-phase Biot-type theory in which sand, gas hydrate, and pore fluid form three homogeneous, interwoven frameworks. This theory is developed using well log compressional and shear wave velocity data from the Mallik 5L-38 permafrost gas hydrate research well in Canada and applied to well log data from hydrate-bearing sands in the Alaskan permafrost, Gulf of Mexico, and northern Cascadia margin. Velocity-based gas hydrate saturation estimates are in good agreement with Nuclear Magneto Resonance and resistivity log estimates over the complete range of observed gas hydrate saturations.

  10. Application of just-in-time manufacturing techniques in radioactive source in well logging industry

    Directory of Open Access Journals (Sweden)

    Atma Yudha Prawira

    2017-03-01

    Full Text Available Nuclear logging is one of major areas of logging development. This paper presents an empirical investigation to bring the drilling and completion of wells from an ill-defined art to a refined sci-ence by using radioactive source to “look and measure” such as formation type, formation dip, porosity, fluid type and numerous other important factors. The initial nuclear logging tools rec-ords the radiation emitted by formation as they were crossed by boreholes. Gamma radiation is used in well logging as it is powerful enough to penetrate the formation and steel casing. The ra-dioactive source is reusable so that after engineer finished the job the radioactive source is sent back to bunker. In this case inventory level of radioactive source is relatively high compared with monthly movement and the company must spend large amount of cost just for inventory. After calculating and averaging the monthly movement in 2014 and 2015, we detected a big pos-sibility to cut the inventory level to reduce the inventory cost.

  11. An NMR log echo data de-noising method based on the wavelet packet threshold algorithm

    International Nuclear Information System (INIS)

    Meng, Xiangning; Xie, Ranhong; Li, Changxi; Hu, Falong; Li, Chaoliu; Zhou, Cancan

    2015-01-01

    To improve the de-noising effects of low signal-to-noise ratio (SNR) nuclear magnetic resonance (NMR) log echo data, this paper applies the wavelet packet threshold algorithm to the data. The principle of the algorithm is elaborated in detail. By comparing the properties of a series of wavelet packet bases and the relevance between them and the NMR log echo train signal, ‘sym7’ is found to be the optimal wavelet packet basis of the wavelet packet threshold algorithm to de-noise the NMR log echo train signal. A new method is presented to determine the optimal wavelet packet decomposition scale; this is within the scope of its maximum, using the modulus maxima and the Shannon entropy minimum standards to determine the global and local optimal wavelet packet decomposition scales, respectively. The results of applying the method to the simulated and actual NMR log echo data indicate that compared with the wavelet threshold algorithm, the wavelet packet threshold algorithm, which shows higher decomposition accuracy and better de-noising effect, is much more suitable for de-noising low SNR–NMR log echo data. (paper)

  12. GammaLog Playback 1.0 - mobile gamma ray spectrometry software

    International Nuclear Information System (INIS)

    Watson, R.J.; Smethurst, M.A.

    2011-01-01

    The Geological Survey of Norway (NGU) operates a mobile gamma ray spectrometer system which can be used in nuclear emergency situations to determine the location and type of orphan sources, or the extent and type of fallout contamination. The system consists of a 20 litre (16 litre downward and 4 litre upward looking) RSX-5 NaI detector and spectrometer, and can be mounted in fixed wing aircraft, helicopters, or vans/cars as appropriate. NGU has developed its own data acquisition and analysis software for this system. GammaLog (Smethurst 2005) controls the acquisition, display, and storage of data from the spectrometer, and performs real-time data analysis including estimation of dose rates and fallout concentrations, and separation of geological and anthropogenic components of the signal. The latter is particularly important where the geological radioisotope signal varies strongly from one place to another, and makes it easier to locate and identify anthropogenic sources which might otherwise be difficult to separate from the geological background signal. A modified version of GammaLog has been developed, GammaLog Playback, which allows the replay of previously acquired GammaLog datasets, while performing similar processing and display as the GammaLog acquisition software. This allows datasets to be reviewed and compared in the field or during post-survey analysis to help plan subsequent measurement strategies.(Au)

  13. Generalized localization for the double trigonometric Fourier series and the Walsh-Fourier series of functions in L log +L log + log +L

    International Nuclear Information System (INIS)

    Bloshanskaya, S K; Bloshanskii, I L; Roslova, T Y

    1998-01-01

    For an arbitrary open set Ω subset of I 2 =[0,1) 2 and an arbitrary function f element of L log + L log + log + L(I 2 ) such that f=0 on Ω the double Fourier series of f with respect to the trigonometric system Ψ=E and the Walsh-Paley system Ψ=W is shown to converge to zero (over rectangles) almost everywhere on Ω. Thus, it is proved that generalized localization almost everywhere holds on arbitrary open subsets of the square I 2 for the double trigonometric Fourier series and the Walsh-Fourier series of functions in the class L log + L log + log + L (in the case of summation over rectangles). It is also established that such localization breaks down on arbitrary sets that are not dense in I 2 , in the classes Φ Ψ (L)(I 2 ) for the orthonormal system Ψ=E and an arbitrary function such that Φ E (u)=o(u log + log + u) as u→∞ or for Φ W (u)=u( log + log + u) 1-ε , 0<ε<1

  14. Permeability log using new lifetime measurements

    International Nuclear Information System (INIS)

    Dowling, D.J.; Boyd, J.F.; Fuchs, J.A.

    1975-01-01

    Comparative measurements of thermal neutron decay time are obtained for a formation after irradiation with a pulsed neutron source. Chloride ions in formation fluids are concentrated by the electrosmosis effect using charged poles on a well logging sonde. The formation is irradiated with fast neutrons and a first comparative measure of the thermal neutron decay time or neutron lifetime is taken. The chloride ions are then dispersed by acoustic pumping with a magnetostrictive transducer. The formation is then again irradiated with fast neutrons and a comparative measure of neutron lifetime is taken. The comparison is a function of the variation in chloride concentration between the two measurements which is related to formation permeability

  15. Pulsed neutron source well logging system

    International Nuclear Information System (INIS)

    Dillingham, M.E.

    1975-01-01

    A pulsed neutron source arrangement is provided in which a sealed cylindrical chamber encloses a rotatable rotor member carrying a plurality of elongated target strips of material which emits neutrons when bombarded with alpha particles emitted by the plurality of source material strips. The rotor may be locked in a so-called ON position by an electromagnetic clutch drive mechanism controllable from the earth's surface so as to permit the making of various types of logs utilizing a continuously emitting neutron source. (Patent Office Record)

  16. On conditional independence and log-convexity

    Czech Academy of Sciences Publication Activity Database

    Matúš, František

    2012-01-01

    Roč. 48, č. 4 (2012), s. 1137-1147 ISSN 0246-0203 R&D Projects: GA AV ČR IAA100750603; GA ČR GA201/08/0539 Institutional support: RVO:67985556 Keywords : Conditional independence * Markov properties * factorizable distributions * graphical Markov models * log-convexity * Gibbs- Markov equivalence * Markov fields * Gaussian distributions * positive definite matrices * covariance selection model Subject RIV: BA - General Mathematics Impact factor: 0.933, year: 2012 http://library.utia.cas.cz/separaty/2013/MTR/matus-0386229.pdf

  17. New radio meteor detecting and logging software

    Science.gov (United States)

    Kaufmann, Wolfgang

    2017-08-01

    A new piece of software ``Meteor Logger'' for the radio observation of meteors is described. It analyses an incoming audio stream in the frequency domain to detect a radio meteor signal on the basis of its signature, instead of applying an amplitude threshold. For that reason the distribution of the three frequencies with the highest spectral power are considered over the time (3f method). An auto notch algorithm is developed to prevent the radio meteor signal detection from being jammed by a present interference line. The results of an exemplary logging session are discussed.

  18. Zope based electronic operation log system - Zlog

    International Nuclear Information System (INIS)

    Yoshii, K.; Satoh, Y.; Kitabayashi, T.

    2004-01-01

    Since January 2004, the Zope based electronic operation logging system, named Zlog, has been running at the KEKB and AR accelerator facilities. Since Zope is the python based open source web application server software and python language is familiar for the members in the KEKB accelerator control group, we have developed the Zlog system rapidly. In this paper, we report the development history and the present status of Zlog system. Also we show some general plug-in components, called Zope products, have been useful for our Zlog development. (author)

  19. Shiitake mushroom production on small diameter oak logs in Ohio

    Science.gov (United States)

    S.M. Bratkovich

    1991-01-01

    Yields of different strains of shiitake mushrooms (Lentinus edodes) were evaluated when produced on small diameter oak logs in Ohio. Logs averaging between 3-4 inches in diameter were inoculated with four spawn strains in 1985.

  20. Log and tree sawing times for hardwood mills

    Science.gov (United States)

    Everette D. Rast

    1974-01-01

    Data on 6,850 logs and 1,181 trees were analyzed to predict sawing times. For both logs and trees, regression equations were derived that express (in minutes) sawing time per log or tree and per Mbf. For trees, merchantable height is expressed in number of logs as well as in feet. One of the major uses for the tables of average sawing times is as a bench mark against...

  1. Log-Log Convexity of Type-Token Growth in Zipf's Systems

    Science.gov (United States)

    Font-Clos, Francesc; Corral, Álvaro

    2015-06-01

    It is traditionally assumed that Zipf's law implies the power-law growth of the number of different elements with the total number of elements in a system—the so-called Heaps' law. We show that a careful definition of Zipf's law leads to the violation of Heaps' law in random systems, with growth curves that have a convex shape in log-log scale. These curves fulfill universal data collapse that only depends on the value of Zipf's exponent. We observe that real books behave very much in the same way as random systems, despite the presence of burstiness in word occurrence. We advance an explanation for this unexpected correspondence.

  2. Data Cleaning Methods for Client and Proxy Logs

    NARCIS (Netherlands)

    Weinreich, H.; Obendorf, H.; Herder, E.; Edmonds, A.; Hawkey, K.; Kellar, M.; Turnbull, D.

    2006-01-01

    In this paper we present our experiences with the cleaning of Web client and proxy usage logs, based on a long-term browsing study with 25 participants. A detailed clickstream log, recorded using a Web intermediary, was combined with a second log of user interface actions, which was captured by a

  3. Sediment transport and soil disturbance after postfire logging.

    Science.gov (United States)

    James D. McIver

    2003-01-01

    Recently there has been considerable debate on the practice of postfire logging, in which burned forests are entered soon after fire to recover commercially valuable trees. Proponents of the practice argue that postfire logging is part of a 'restoration package' that can be used to control erosion (e.g., contour logging) and can help to mitigate costs of...

  4. Why, What, and How to Log? Lessons from LISTEN

    Science.gov (United States)

    Mostow, Jack; Beck, Joseph E.

    2009-01-01

    The ability to log tutorial interactions in comprehensive, longitudinal, fine-grained detail offers great potential for educational data mining--but what data is logged, and how, can facilitate or impede the realization of that potential. We propose guidelines gleaned over 15 years of logging, exploring, and analyzing millions of events from…

  5. Economic incentives exist to support measures to reduce illegal logging

    Science.gov (United States)

    J.A. Turner; J. Buongiorno; A. Katz; S. Zhu; R. Li

    2008-01-01

    Three studies of the global economic implications of eliminating illegal logging are summarized. Processors of illegally sourced wood would lose from the elimination of illegal logging through high prices for logs and decreased production of wood products. Associated with these changes could be losses in employment and income. Beyond these losses to the processing...

  6. A survey of animal-powered logging in Alabama

    Science.gov (United States)

    Christopher W. Toms; Mark R. Dubois; John C. Bliss; John H. Wilhoit; Robert B. Rummer

    2001-01-01

    In a state with a very large, highly mechanized timber harvesting industry, animal-powered logging still occupies a niche in Alabama as a small-scale harvesting alternative. This article summarizes the results from a study that examined the extent of animal logging in Alabama. We investigated this topic by asking who is logging with animals, where are they working,...

  7. Interactive machine learning for postprocessing CT images of hardwood logs

    Science.gov (United States)

    Erol Sarigul; A. Lynn Abbott; Daniel L. Schmoldt

    2003-01-01

    This paper concerns the nondestructive evaluation of hardwood logs through the analysis of computed tomography (CT) images. Several studies have shown that the commercial value of resulting boards can be increased substantially if log sawing strategies are chosen using prior knowledge of internal log defects. Although CT imaging offers a potential means of obtaining...

  8. Financial and Economic Analysis of Reduced Impact Logging

    Science.gov (United States)

    Tom Holmes

    2016-01-01

    Concern regarding extensive damage to tropical forests resulting from logging increased dramatically after World War II when mechanized logging systems developed in industrialized countries were deployed in the tropics. As a consequence, tropical foresters began developing logging procedures that were more environmentally benign, and by the 1990s, these practices began...

  9. Environmental effects of postfire logging: literature review and annotated bibliography.

    Science.gov (United States)

    James D. McIver; Lynn Starr

    2000-01-01

    The scientific literature on logging after wildfire is reviewed, with a focus on environmental effects of logging and removal of large woody structure. Rehabilitation, the practice of planting or seeding after logging, is not reviewed here. Several publications are cited that can be described as “commentaries,” intended to help frame the public debate. We review 21...

  10. Utilization and cost of log production from animal loging operations

    Science.gov (United States)

    Suraj P. Shrestha; Bobby L. Lanford; Robert B. Rummer; Mark Dubois

    2006-01-01

    Forest harvesting with animals is a labor-intensive operation. It is expensive to use machines on smaller woodlots, which require frequent moves if mechanically logged. So, small logging systems using animals may be more cost effective. In this study, work sampling was used for five animal logging operations in Alabama to measure productive and non-productive time...

  11. Development of regional stump-to-mill logging cost estimators

    Science.gov (United States)

    Chris B. LeDoux; John E. Baumgras

    1989-01-01

    Planning logging operations requires estimating the logging costs for the sale or tract being harvested. Decisions need to be made on equipment selection and its application to terrain. In this paper a methodology is described that has been developed and implemented to solve the problem of accurately estimating logging costs by region. The methodology blends field time...

  12. Ultrafast CT scanning of an oak log for internal defects

    Science.gov (United States)

    Francis G. Wagner; Fred W. Taylor; Douglas S. Ladd; Charles W. McMillin; Fredrick L. Roder

    1989-01-01

    Detecting internal defects in sawlogs and veneer logs with computerized tomographic (CT) scanning is possible, but has been impractical due to the long scanning time required. This research investigated a new scanner able to acquire 34 cross-sectional log scans per second. This scanning rate translates to a linear log feed rate of 85 feet (25.91 m) per minute at one...

  13. Technology development for high temperature logging tools

    Energy Technology Data Exchange (ETDEWEB)

    Veneruso, A.F.; Coquat, J.A.

    1979-01-01

    A set of prototype, high temperature logging tools (temperature, pressure and flow) were tested successfully to temperatures up to 275/sup 0/C in a Union geothermal well during November 1978 as part of the Geothermal Logging Instrumentation Development Program. This program is being conducted by Sandia Laboratories for the Department of Energy's Division of Geothermal Energy. The progress and plans of this industry based program to develop and apply the high temperature instrumentation technology needed to make reliable geothermal borehole measurements are described. Specifically, this program is upgrading existing sondes for improved high temperature performance, as well as applying new materials (elastomers, polymers, metals and ceramics) and developing component technology such as high temperature cables, cableheads and electronics to make borehole measurements such as formation temperature, flow rate, high resolution pressure and fracture mapping. In order to satisfy critical existing needs, the near term goal is for operation up to 275/sup 0/C and 7000 psi by the end of FY80. The long term goal is for operation up to 350/sup 0/C and 20,000 psi by the end of FY84.

  14. Public PCs: Log Out or Lose Out

    CERN Multimedia

    Computer Security Team

    2013-01-01

    Do you regularly use one of the public Windows or Linux terminals in the CERN library or in front of the Users' Office? Or do you often give presentations or run meetings, workshops or conferences? Did you recently attend a training session in the CERN Training Centre? If you answered at least once with “yes”, we have a plea for you: LOG OUT when done in order to protect your data!   You might recall that CERN considers that “Your Privacy is Paramount”. But this does not come for free. In the few past months, we have received several reports from vigilant people who have spotted open user sessions on public PCs at CERN. Those users simply forgot to log out once their work, training or meeting was over. Their session continued without them being present. Worse, with CERN using a central Single Sign-On (SSO) portal, their login credentials would allow a malicious person at CERN to use those credentials to access that user’s mailbox, DFS ...

  15. Dual excitation acoustic paramagnetic logging tool

    Energy Technology Data Exchange (ETDEWEB)

    Vail, III, William B. (Bothell, WA)

    1989-01-01

    New methods and apparatus are disclosed which allow measurement of the presence of oil and water in gelogical formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleous present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described.

  16. Radiation incident in oil well logging

    International Nuclear Information System (INIS)

    Lozada, J.A.

    1998-01-01

    On June 4th 1997 equipment failure and violation of approved procedures by a crew of workers initiated a series of events that resulted in the unnecessary exposure to neutron and gamma radiation, from a 666 GBq Am 241 Be source, of forty two workers from a well logging company in Venezuela. Due to the presence of dry mud or drilling fluids inside the logging tool, the nosepiece was screwed off the rest of the source holder; this piece was mistaken for the entire source holder thus leaving the source inside the tool. The tool was labelled for maintenance and electronic laboratory personal worked near the source for seven hours before they identify its presence. As soon as the incident was detected a contingency plan was implemented and the source could be retrieved from the tool and placed in its shipping container. The TLD badges indicate doses well below the annual limit of 20 mSv, and none of the workers involved in the incident seem to show serious health consequences from it. After the incident, in order to avoid the occurrence of similar situations, a better source and tool maintenance program was implemented, all the workers were re-trained, and area monitors were installed in all operations bases. (author)

  17. Rill erosion in burned and salvage logged western montane forests: Effects of logging equipment type, traffic level, and slash treatment

    Science.gov (United States)

    J. W. Wagenbrenner; P. R. Robichaud; R. E. Brown

    2016-01-01

    Following wildfires, forest managers often consider salvage logging burned trees to recover monetary value of timber, reduce fuel loads, or to meet other objectives. Relatively little is known about the cumulative hydrologic effects of wildfire and subsequent timber harvest using logging equipment. We used controlled rill experiments in logged and unlogged (control)...

  18. Use of pulsed neutron logging to evaluate perforation washing

    International Nuclear Information System (INIS)

    Dimon, C.A.

    1986-01-01

    This invention relates to the use of pulsed neutron logging techniques before and after perforation washing operations are performed to evaluate the degree of success of the perforation washing operations. Well logging operations of a type designed to respond to the difference between a formation immediately behind the well sheath and voids in the formation are performed both before and after the perforation washing operation. differences between the two resulting logs are then indicative of voids created by perforation washing. In a preferred embodiment, pulsed neutron logging is used as the logging technique, while a weighted brine having a high absorption cross section to pulsed neutrons is used as the perforation washing fluid

  19. Study of the reservoirs of Jurassic and Cretaceous periods in the south-cast slope of Central Kara-Kum vault using combination of acoustic logging, neutron-gamma logging, gamma logging, and electrical logging

    International Nuclear Information System (INIS)

    Meredov, T.M.; Baranov, M.I.

    1978-01-01

    Considered is the possibility of application of the combination of neutron-gamma logging, gamma logging al partitioncoustic logging and electrical logging to lithologica of sections, discovery reservoir layers in carbonate and terrigeneous sections as well as quantitative estimation of the porosity coefficients values at prospecting areas in the south-east slope of Central Kara-Kum vault. Neutron-gamma logging mostly makes it possible to partition carbonate rocks into limestones, dolomites and their interstitial variaties and to indicate sand stone layers with different degree of carbonate content

  20. KFM 01A. Q-logging

    International Nuclear Information System (INIS)

    Barton, Nick

    2003-03-01

    The first Forsmark potential repository site borehole KFM 01A provided core from 101.8 to 1000.7 m depth. This was independently Q-logged during a two-day period (19th-20th February, 2003), without access to BORMAP results or regional jointing frequencies or orientations. The Q-logging was intended to be an independent check for subsequent BORMAP-derived Q-parameter estimation. The Q-logging was accomplished using the manually-recorded 'histogram method' which allows the logger to enter Q-parameter ranges and depths directly into the appropriate histograms, which facilitates subsequent data processing using Excel spreadsheets. Successive pairs of core boxes, which contain an average of 11 meters of core in ten rows, were the source of ten opinions of each of the six Q-parameters, giving a total of 4920 recordings of Q-parameter values for the 164 core boxes. Data processing was divided into several parts, with successively increasing detail. The report therefore contains Q-histograms for the whole core, for four identified fracture(d) zones combined as if one unit, and then for the whole core minus these fracture(d) zones. This background rock mass quality is subsequently divided into nine depth zones or slices, and trends of variation with depth are tabulated. The four identified fracture(d) zones, which are actually of reasonable quality, are also analysed separately, and similarities and subtle differences are discerned between them. The overall quality of this first core is very good to excellent, with Q(mean) of 48.4, and a most frequent Q-value of 100. The range of quality is from 2.1 to 2130, which is the complete upper half of the six order of magnitude Q scale. Even the relatively fracture(d) zones, representing some 13% of the 900 m cored, have a combined Q(mean) of 13.9 and a range of quality of 2.1 to 150

  1. Method and apparatus for logging inclined earth boreholes

    International Nuclear Information System (INIS)

    Youmans, A.H.

    1981-01-01

    An improved technique is provided for comparing the velocity of an elongated well logging instrument traversing an inclined earth borehole with the playout velocity of the well logging cable at the earth's surface to control both the cable hoist drum rotation and the rate of movement of the subsurface instrument and thus insure cable playout is in equilibrium with the logging instrument movement. Method and apparatus are described for detecting any reduction in movement of the logging instrument through the borehole and for reducing the velocity of the logging cable playout in response thereto by reducing drum rotation. Further, when the velocity of cable playout slows to a preselected value, a monitoring circuit generates control signals which actuate a means of power attached to or integral with the logging instrument which, upon initiation, apply a force to move the logging instrument upward or downward within the borehole

  2. DOE-Grand Junction logging model data synopsis

    International Nuclear Information System (INIS)

    Mathews, M.A.; Koizumi, C.J.; Evans, H.B.

    1978-05-01

    This synopsis provides the available data concerning the logging models at the DoE-Grand Junction facility, to date (1976). Because gamma-ray logs are used in uranium exploration to estimate the grade (percent U 3 O 8 ) and the thickness of uranium ore zones in exploration drill holes, logging models are required to calibrate the gamma-ray logging equipment in order to obtain accuracy, uniformity, standardization, and repeatability during logging. This quality control is essential for accurate ore reserve calculations and for estimates of ore potential. The logging models at the DoE-Grand Junction facility are available for use by private industry in calibrating their gamma-ray logging equipment. 21 figures, 26 tables

  3. Applicability estimation of flowmeter logging for detecting hydraulic pass

    International Nuclear Information System (INIS)

    Miyakawa, Kimio; Tanaka, Yasuji; Tanaka, Kazuhiro

    1997-01-01

    Estimation of the hydraulic pass governing hydrogeological structure contributes significantly to the siting HLW repository. Flowmeter logging can detect hydraulic passes by measuring vertical flow velocity of groundwater in the borehole. We reviewed application of this logging in situ. The hydraulic pass was detected with combination of ambient flow logging, with pumping and/or injecting induced flow logging. This application showed that the flowmeter logging detected hydraulic passes conveniently and accurately compared with other hydraulic tests. Hydraulic conductivity by using flowmeter logging was assessed above 10 -6 m/sec and within one order from comparison with injection packer tests. We suggest that appropriate application of the flowmeter logging for the siting is conducted before hydraulic tests because test sections and monitoring sections are decided rationally for procurement of quantitative hydraulic data. (author)

  4. Logging-while-drilling (LWD) pressure test

    Energy Technology Data Exchange (ETDEWEB)

    Thirud, Aase P.

    2003-07-01

    Statoil and Halliburton have completed a successful test of a new ground-breaking formation evaluation technology on the Norwegian shelf. An LWD formation tester, the GeoTapTM sensor, was used to quantify formation pressure during drilling operations. The inaugural job was completed by Halliburton's Sperry-Sun product service line onboard the Bideford Dolphin at the Borg Field while drilling a horizontal production well in the Vigdis Extension development. The GeoTap tool, part of Sperry-Sun's StellarTM MWD/LWT suite, was run in combination with a complete logging-while-drilling sensor package and the Geo-Pilot rotary steerable drilling system. Repeat formation pressures were taken and successfully transmitted to surface. This is the first time this type of technology has been successfully applied on the Norwegian shelf.

  5. Neutron die-away well logging

    International Nuclear Information System (INIS)

    Jacobson, L.A.

    1976-01-01

    Neutron die-away well logging is extensively used for the location and monitoring of hydrocarbon zones in cased wells. Casing prohibits the use of conventional open-hole electrical resistivity methods. Through an appropriate interpretation of the measured capture cross-section, it is possible to determine the fractional hydrocarbon content of the rock pore volume, provided that the interstitial water is moderately saline (Σ/sub w/ greater than or equal to .035 cm -1 ). Special sealed D-T accelerator tubes and high voltage supplies have been developed for this purpose. They must fit into a 25 mm design circle and operate at 175 0 C, producing approximately 10 8 neutron/sec average in repetitive bursts. In the Schlumberger method an electronic servo-system adjusts burst and measure-gate timing to minimize statistical uncertainty regardless of die-away time

  6. Simulation Control Graphical User Interface Logging Report

    Science.gov (United States)

    Hewling, Karl B., Jr.

    2012-01-01

    One of the many tasks of my project was to revise the code of the Simulation Control Graphical User Interface (SIM GUI) to enable logging functionality to a file. I was also tasked with developing a script that directed the startup and initialization flow of the various LCS software components. This makes sure that a software component will not spin up until all the appropriate dependencies have been configured properly. Also I was able to assist hardware modelers in verifying the configuration of models after they have been upgraded to a new software version. I developed some code that analyzes the MDL files to determine if any error were generated due to the upgrade process. Another one of the projects assigned to me was supporting the End-to-End Hardware/Software Daily Tag-up meeting.

  7. Development of an Intelligent System to Synthesize Petrophysical Well Logs

    Directory of Open Access Journals (Sweden)

    Morteza Nouri Taleghani

    2013-07-01

    Full Text Available Porosity is one of the fundamental petrophysical properties that should be evaluated for hydrocarbon bearing reservoirs. It is a vital factor in precise understanding of reservoir quality in a hydrocarbon field. Log data are exceedingly crucial information in petroleum industries, for many of hydrocarbon parameters are obtained by virtue of petrophysical data. There are three main petrophysical logging tools for the determination of porosity, namely neutron, density, and sonic well logs. Porosity can be determined by the use of each of these tools; however, a precise analysis requires a complete set of these tools. Log sets are commonly either incomplete or unreliable for many reasons (i.e. incomplete logging, measurement errors, and loss of data owing to unsuitable data storage. To overcome this drawback, in this study several intelligent systems such as fuzzy logic (FL, neural network (NN, and support vector machine are used to predict synthesized petrophysical logs including neutron, density, and sonic. To accomplish this, the petrophysical well logs data were collected from a real reservoir in one of Iran southwest oil fields. The corresponding correlation was obtained through the comparison of synthesized log values with real log values. The results showed that all intelligent systems were capable of synthesizing petrophysical well logs, but SVM had better accuracy and could be used as the most reliable method compared to the other techniques.

  8. Pulsed neutron uranium borehole logging with prompt fission neutrons

    International Nuclear Information System (INIS)

    Bivens, H.M.; Smith, G.W.; Jensen, D.H.

    1976-01-01

    The gross count natural gamma log normally used for uranium borehole logging is seriously affected by disequilibrium. Methods for the direct measurement of uranium, such as neutron logging, which are not affected by disequilibrium have been the object of considerable effort in recent years. This paper describes a logging system for uranium which uses a small accelerator to generate pulses of 14 MeV neutrons to detect and assay uranium by the measurement of prompt fission neutrons in the epithermal energy range. After an initial feasibility study, a prototype logging probe was built for field evaluation which began in January 1976. Physical and operational characteristics of the prototype probe, the neutron tube-transformer assembly, and the neutron tube are described. In logging operations, only the epithermal prompt fission neutrons detected between 250 microseconds to 2500 microseconds following the excitation neutron pulse are counted. Comparison of corrected neutron logs with the conventional gross count natural gamma logs and the chemical assays of cores from boreholes are shown. The results obtained with this neutron probe clearly demonstrate its advantages over the gross count natural gamma log, although at this time the accuracy of the neutron log assay is not satisfactory under some conditions. The necessary correction factors for various borehole and formation parameters are being determined and, when applied, should improve the assay accuracy

  9. Intelligent approaches for the synthesis of petrophysical logs

    International Nuclear Information System (INIS)

    Rezaee, M Reza; Kadkhodaie-Ilkhchi, Ali; Alizadeh, Pooya Mohammad

    2008-01-01

    Log data are of prime importance in acquiring petrophysical data from hydrocarbon reservoirs. Reliable log analysis in a hydrocarbon reservoir requires a complete set of logs. For many reasons, such as incomplete logging in old wells, destruction of logs due to inappropriate data storage and measurement errors due to problems with logging apparatus or hole conditions, log suites are either incomplete or unreliable. In this study, fuzzy logic and artificial neural networks were used as intelligent tools to synthesize petrophysical logs including neutron, density, sonic and deep resistivity. The petrophysical data from two wells were used for constructing intelligent models in the Fahlian limestone reservoir, Southern Iran. A third well from the field was used to evaluate the reliability of the models. The results showed that fuzzy logic and artificial neural networks were successful in synthesizing wireline logs. The combination of the results obtained from fuzzy logic and neural networks in a simple averaging committee machine (CM) showed a significant improvement in the accuracy of the estimations. This committee machine performed better than fuzzy logic or the neural network model in the problem of estimating petrophysical properties from well logs

  10. One less trip : logging with less tripping, more protection

    Energy Technology Data Exchange (ETDEWEB)

    Byfield, M.

    2005-12-15

    New logging technology by Datalog Technology Inc. was described. Logging-while-tripping (LWT) technology uses a slim petrophysical sensor package that is moved to the targeted geological formation through a drill pipe, which reduces the exposure to vibration and shock involved in logging-while-drilling (LWD). The equipment features standard components in a patented configuration and comes in 2 segments: the receiver sub and the sensor package electronics. A receiver sub is inserted into the bottomhole assembly at the end of the drill string. Drilling progresses with the LWT sub in the bottomhole assembly until the borehole approaches the logging depth. The sensor package and electronics are then lowered into the drill string. If the well is horizontal, rig pumps push the package into the drill string until it lands in the LWT sub. Drill pipes are moved across the zone of interest and logs are recorded on downhole memory contained within the LWT package. As the logging operation progresses, a depth recorder at the surface records depth information along with the downhole recorders. When logging is completed, downhole tools are retrieved, and data downloaded from the LWT onboard memory is merged with the surface depth information to generate well logs. Retrieval via the drill string greatly reduces the risk of losing the logging gear, which contains radioactive material. Federal officials now routinely insist on extensive fishing operations to retrieve lost tools. If a well gets a gas kick while logging is in progress, the operator can still pump down mud or close the blowout preventer rams if necessary, and save time in determining where to perforate shallow gas wells. Compensated neutron logs, gamma rays, spectrum gamma rays, and induction have been tested with the LWT system. It was concluded that Petro-Canada has deployed the logs recently and has achieved results that compared satisfactorily with conventional logs. 2 figs.

  11. Water saturation in shaly sands: logging parameters from log-derived values

    International Nuclear Information System (INIS)

    Miyairi, M.; Itoh, T.; Okabe, F.

    1976-01-01

    The methods are presented for determining the relation of porosity to formation factor and that of true resistivity of formation to water saturation, which were investigated through the log interpretation of one of the oil and gas fields of northern Japan Sea. The values of the coefficients ''a'' and ''m'' in porosity-formation factor relation are derived from cross-plot of porosity and resistivity of formation corrected by clay content. The saturation exponent ''n'' is determined from cross-plot of porosity and resistivity index on the assumption that the product of porosity and irreducible water saturation is constant. The relation of porosity to irreducible water saturation is also investigated from core analysis. The new logging parameters determined from the methods, a = 1, m = 2, n = 1.4, improved the values of water saturation by 6 percent in average, and made it easy to distinguish the points which belong to the productive zone and ones belonging to the nonproductive zone

  12. Geophysical borehole logging in Lavia borehole - results and interpretation of sonic and tube wave measurements

    International Nuclear Information System (INIS)

    Andersson, P.; Stenberg, L.

    1985-02-01

    Swedish Nuclear Fuel and Waste Management Co, SKB has been contracted by Industrial Power Company LTD, TVO to perform geophysical logging in a borehole at Lavia in Western Finland. The logging has been conducted by Swedish Geological Co, SGAB in accordance with an agreement for cooperation with SKB. The depth of the borehole is 1001 m, diameter 56 mm and inclination 10-20 degrees to the vertical. The aim of the logging was to determine the various geophysical parameters in the borehole in order to interpret and understand the rock mass properties in the vicinity of the borehole. According to the contract the report covers the following main objectives: a technical description of the field work and the equipment used; a review of the theoretical base for the sonic and tube wave methods; an interpretation and presentation of the results obtained by sonic and tube wave mesurements. The evaluation of the sonic and tube wave measurements shows good correlation. On a qualitative basis there seems to be a correlation between tube wave generating points, the relative tube wave amplitudes and the hydraulic conductivity measurements performed as hydraulical tests between packers in the borehole. The low velocity anamalies in the sonic log are mainly caused by tectonic features like fractures and fracture zones but to some extent also by contacts between granite and diorite. The estimation of elastic properties of the rock mass from observation of tube wave velocity are in accordance with laboratory determinations made on core samples. (author)

  13. Rill erosion in burned and salvage logged western montane forests: Effects of logging equipment type, traffic level, and slash treatment

    Science.gov (United States)

    Wagenbrenner, J. W.; Robichaud, P. R.; Brown, R. E.

    2016-10-01

    Following wildfires, forest managers often consider salvage logging burned trees to recover monetary value of timber, reduce fuel loads, or to meet other objectives. Relatively little is known about the cumulative hydrologic effects of wildfire and subsequent timber harvest using logging equipment. We used controlled rill experiments in logged and unlogged (control) forests burned at high severity in northern Montana, eastern Washington, and southern British Columbia to quantify rill overland flow and sediment production rates (fluxes) after ground-based salvage logging. We tested different types of logging equipment-feller-bunchers, tracked and wheeled skidders, and wheeled forwarders-as well as traffic levels and the addition of slash to skid trails as a best management practice. Rill experiments were done at each location in the first year after the fire and repeated in subsequent years. Logging was completed in the first or second post-fire year. We found that ground-based logging using heavy equipment compacted soil, reduced soil water repellency, and reduced vegetation cover. Vegetation recovery rates were slower in most logged areas than the controls. Runoff rates were higher in the skidder and forwarder plots than their respective controls in the Montana and Washington sites in the year that logging occurred, and the difference in runoff between the skidder and control plots at the British Columbia site was nearly significant (p = 0.089). Most of the significant increases in runoff in the logged plots persisted for subsequent years. The type of skidder, the addition of slash, and the amount of forwarder traffic did not significantly affect the runoff rates. Across the three sites, rill sediment fluxes were 5-1900% greater in logged plots than the controls in the year of logging, and the increases were significant for all logging treatments except the low use forwarder trails. There was no difference in the first-year sediment fluxes between the feller

  14. Aespoe Hard Rock Laboratory. BIPS logging in borehole KAS09

    International Nuclear Information System (INIS)

    Gustafsson, Jaana; Gustafsson, Christer

    2010-01-01

    This report includes the data gained in BIPS logging performed at the Aespoe Hard Rock Laboratory. The logging operation presented here includes BIPS logging in the core drilled borehole KAS09. The objective for the BIPS logging was to observe the condition of KAS09 in order to restore the borehole in the hydrogeological monitoring programme.All measurements were conducted by Malaa Geoscience AB on October 9th 2009. The objective of the BIPS logging is to achieve information of the borehole including occurrence of rock types as well as determination of fracture distribution and orientation. This report describes the equipment used as well as the measurement procedures and data gained. For the BIPS survey, the result is presented as images. The basic conditions of the BIPS logging for geological mapping and orientation of structures are satisfying for borehole KAS09, although induced affects from the drilling on the borehole walls limit the visibility

  15. Aespoe Hard Rock Laboratory. BIPS logging in borehole KAS09

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Jaana; Gustafsson, Christer (Malaa Geoscience AB (Sweden))

    2010-01-15

    This report includes the data gained in BIPS logging performed at the Aespoe Hard Rock Laboratory. The logging operation presented here includes BIPS logging in the core drilled borehole KAS09. The objective for the BIPS logging was to observe the condition of KAS09 in order to restore the borehole in the hydrogeological monitoring programme.All measurements were conducted by Malaa Geoscience AB on October 9th 2009. The objective of the BIPS logging is to achieve information of the borehole including occurrence of rock types as well as determination of fracture distribution and orientation. This report describes the equipment used as well as the measurement procedures and data gained. For the BIPS survey, the result is presented as images. The basic conditions of the BIPS logging for geological mapping and orientation of structures are satisfying for borehole KAS09, although induced affects from the drilling on the borehole walls limit the visibility

  16. Geophysical well logging operations and log analysis in Geothermal Well Desert Peak No. B-23-1

    Energy Technology Data Exchange (ETDEWEB)

    Sethi, D.K.; Fertl, W.H.

    1980-03-01

    Geothermal Well Desert Peak No. B-23-1 was logged by Dresser Atlas during April/May 1979 to a total depth of 2939 m (9642 ft). A temperature of 209/sup 0/C (408/sup 0/F) was observed on the maximum thermometer run with one of the logging tools. Borehole tools rated to a maximum temperature of 204.4/sup 0/C (400/sup 0/F) were utilized for logging except for the Densilog tool, which was from the other set of borehole instruments, rated to a still higher temperature, i.e., 260/sup 0/C (500/sup 0/F). The quality of the logs recorded and the environmental effects on the log response have been considered. The log response in the unusual lithologies of igneous and metamorphic formations encountered in this well could be correlated with the drill cutting data. An empirical, statistical log interpretation approach has made it possible to obtain meaningful information on the rocks penetrated. Various crossplots/histograms of the corrected log data have been generated on the computer. These are found to provide good resolution between the lithological units in the rock sequence. The crossplotting techniques and the statistical approach were combined with the drill cutting descriptions in order to arrive at the lithological characteristics. The results of log analysis and recommendations for logging of future wells have been included.

  17. Digital data monitoring display and logging

    International Nuclear Information System (INIS)

    Ficaro, E.P.; Wehe, D.K.

    1987-01-01

    A digital data acquisition system for monitoring plant variables has been designed and implemented at the University of Michigan's Ford Nuclear Reactor (FNR), a 2 Megawatt, open-pool, research reactor. The digital data provided by this system is useful for: closed loop control, real time experimental calculations, advanced simulation-as-knowledge techniques, improved operator training, and expert system applications. The purpose of this paper is to discuss the transition to the digital data world and the anticipated applications and benefits

  18. Circular induction accelerator for borehole logging

    International Nuclear Information System (INIS)

    Chen, F.K.; Bertozzi, W.; Corris, G.W.; Diamond, W.; Doucet, J.A.; Schweitzer, J.S.

    1992-01-01

    This patent describes a downhole logging sonde adapted to be moved through a borehole, a source of gamma rays in the sonde for irradiating earth formations traversed by the borehole, one or more gamma ray detectors for detecting gamma rays scattered back to the sonde from the irradiated earth formations, and means for transmitting signals representative of the detected gamma rays to the earth's surface for processing. This patent describes improvement in the gamma ray source comprises a magnetic induction particle accelerator, including: a magnetic circuit having a field magnet, generally circular opposed pole pieces, and a core magnet metal ions from the group consisting of Mn, Zn and Ni; an excitation circuit including a field coil surrounding the field magnet and the core magnet and a core coil surrounding the central axially leg of the core magnet; an annular acceleration chamber interposed between the pole pieces; means for applying time-varying acceleration voltage pulses across the primary excitation circuit; means for injecting charged particles into orbit within the acceleration chamber; means for compressing the particle orbits to trap particles within generally circular orbits within the acceleration chamber; means for generating a particle accelerating magnetic flux in the magnetic circuit; and means for ejecting charged particles from the generally circular orbits and into contact with a target to produce gamma ray photons

  19. Acoustic and Optical Televiewer Borehole Logging

    International Nuclear Information System (INIS)

    Ahmad Hasnulhadi Che Kamaruddin; Nik Marzukee Nik Ibrahim; Zaidi Ibrahim; Nurul Wahida Ahmad Khairuddin; Azmi Ibrahim

    2016-01-01

    This review paper is focused on Borehole Televiewer. Borehole Televiewer or (BHTV) was used to obtain high-resolution acoustical images from the borehole wall. A probe with a high resolution downward looking camera is used. The camera has specific optics (a conical mirror with a ring of bulbs) with just one shot needed to capture the entire borehole circumference as a 360 panoramic view. Settings similar to traditional cameras (exposure, quality, light, frame rate and resolution) make it effective in almost any type of borehole fluid. After each shot, a series of horizontal pixel strings are acquired, giving a rasterized RGB picture in real-time which is transmitted to the console and finally to a monitor. The orientation device embedded in the tool, which is made of 3 inclinometers and 3 magnetometers, allows the inclination and azimuth of the probe to be computed in real-time, correctly orienting the borehole images. Besides, Acoustic and Optical Televiewer has been introduced as its advanced in technological research. Its logging has been successfully applied to geotechnical investigations and mineral exploration (Schepers et al., 2001) due to advances in beam focusing, increased dynamic range, digital recording techniques, and digital data processing (Schepers, 1991). Thus, this paper will go through to the basic principle of (BHTV) as one type of data collection today. (author)

  20. Acoustic reflection log in transversely isotropic formations

    Science.gov (United States)

    Ronquillo Jarillo, G.; Markova, I.; Markov, M.

    2018-01-01

    We have calculated the waveforms of sonic reflection logging for a fluid-filled borehole located in a transversely isotropic rock. Calculations have been performed for an acoustic impulse source with the characteristic frequency of tens of kilohertz that is considerably less than the frequencies of acoustic borehole imaging tools. It is assumed that the borehole axis coincides with the axis of symmetry of the transversely isotropic rock. It was shown that the reflected wave was excited most efficiently at resonant frequencies. These frequencies are close to the frequencies of oscillations of a fluid column located in an absolutely rigid hollow cylinder. We have shown that the acoustic reverberation is controlled by the acoustic impedance of the rock Z = Vphρs for fixed parameters of the borehole fluid, where Vph is the velocity of horizontally propagating P-wave; ρs is the rock density. The methods of waveform processing to determine the parameters characterizing the reflected wave have been discussed.

  1. Cost of skid roads for arch logging in West Virginia

    Science.gov (United States)

    George R., Jr. Trimble; Carl R. Barr

    1960-01-01

    In the mountain hardwood country of the northern Appalachians, tree-length skidding with tractor and arch has proved to be economical logging. One essential part of this type of logging is that tree-length logs are winched to the skid roads: tractor and arch do not run around through the woods. Winching distance is commonly 200 to 300 feet; and occasionally an extra...

  2. Western tight gas sands advanced logging workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, J B; Carroll, Jr, H B [eds.

    1982-04-01

    An advanced logging research program is one major aspect of the Western Tight Sands Program. Purpose of this workshop is to help BETC define critical logging needs for tight gas sands and to allow free interchange of ideas on all aspects of the current logging research program. Sixteen papers and abstracts are included together with discussions. Separate abstracts have been prepared for the 12 papers. (DLC)

  3. An artificial intelligence approach to well log correlation

    International Nuclear Information System (INIS)

    Startzman, R.A.; Kuo, T.B.

    1986-01-01

    This paper shows how an expert computer system was developed to correlate two well logs in at least moderately difficult situations. A four step process was devised to process log trace information and apply a set of rules to identify zonal correlations. Some of the advantages and problems with the artificial intelligence approach are shown using field logs. The approach is useful and, if properly and systematically applied, it can result in good correlations

  4. Geophysical logging studies in the Snake River Plain Aquifer at the Idaho National Engineering Laboratory: Wells 44, 45, and 46

    International Nuclear Information System (INIS)

    Morin, R.H.; Paillet, F.L.; Taylor, T.A.; Barrash, W.

    1993-01-01

    A geophysical logging program was undertaken to vertically profile changes in the hydrology and hydrochemistry of the Snake River Plain aquifer underlies the Idaho National Engineering Laboratory (INEL). Field investigations were concentrated within an area west of the Idaho Chemical Processing Plant (ICPP) in three wells that penetrated the upper 190 feet of the aquifer. The logs obtained in these wells consisted of temperature, caliper, nuclear (neutron porosity and gamma-gama density), natural gamma, borehole televiewer, gamma spectral, and thermal flowmeter (with and without pumping). The nuclear, caliper, and televiewer logs are used to delineate individual basalt flows or flow units and to recognize breaks between flows or flow units at interflow contact zones and sedimentary interbeds. The temperature logs and flowmeter measurements obtained under ambient hydraulic head conditions identified upward fluid-circulation patterns in the three wells. Gamma-spectral analyses performed at several depths in each well showed that the predominant source of gamma radiation in the formation at this site originates mainly from potassium ( 40 K). However, 137 Cesium was detected at 32 feet below land surface in well 45. An empirical investigation of the effect of source-receiver spacing on the response of the neutron-porosity logging tool was attempted in an effort to understand the conditions under which this tool might be applied to large-diameter boreholes in-unsaturated formations

  5. Towards an entropy-based analysis of log variability

    DEFF Research Database (Denmark)

    Back, Christoffer Olling; Debois, Søren; Slaats, Tijs

    2017-01-01

    the development of hybrid miners: given a (sub-)log, can we determine a priori whether the log is best suited for imperative or declarative mining? We propose using the concept of entropy, commonly used in information theory. We consider different measures for entropy that could be applied and show through...... experimentation on both synthetic and real-life logs that these entropy measures do indeed give insights into the complexity of the log and can act as an indicator of which mining paradigm should be used....

  6. Towards an Entropy-based Analysis of Log Variability

    DEFF Research Database (Denmark)

    Back, Christoffer Olling; Debois, Søren; Slaats, Tijs

    2018-01-01

    the development of hybrid miners: given a log, can we determine a priori whether the log is best suited for imperative or declarative mining? We propose using the concept of entropy, commonly used in information theory. We consider different measures for entropy that could be applied and show through...... experimentation on both synthetic and real-life logs that these entropy measures do indeed give insights into the complexity of the log and can act as an indicator of which mining paradigm should be used....

  7. Real Time Face Quality Assessment for Face Log Generation

    DEFF Research Database (Denmark)

    Kamal, Nasrollahi; Moeslund, Thomas B.

    2009-01-01

    Summarizing a long surveillance video to just a few best quality face images of each subject, a face-log, is of great importance in surveillance systems. Face quality assessment is the back-bone for face log generation and improving the quality assessment makes the face logs more reliable....... Developing a real time face quality assessment system using the most important facial features and employing it for face logs generation are the concerns of this paper. Extensive tests using four databases are carried out to validate the usability of the system....

  8. Systematic logging utilizing a log sheet designed for drill core descriptions. An example in uranium exploration activities

    International Nuclear Information System (INIS)

    Sasao, Eiji; Tsuruta, Tadahiko; Iida, Yoshimasa

    2000-01-01

    We describe the log sheets used during uranium exploration activities for unconformity-related uranium deposits by JNC. The purpose of using the logging sheets is to standardize the objects which all geologists must observe and for data quality assurance. The log sheets are a three-part set describing basement lithology, sandstone lithology and geotechnics. We devised our own log sheets to describe both the sandstone and the underlying basement rock when we started exploration in Athabasca Basin, Canada. We modified the sheets to gain a better understanding of the geological features related to uranium mineralization, and made final improvements to satisfy required quality based on the criteria of descriptive objects and accuracy. Use of the log sheets resulted in effective performance of core logging and improvement in the display of data. (author)

  9. Radioprotection guidelines to the elaboration of a specific standard for the licensing of radioactive facilities on the practice of oil and gas well logging

    International Nuclear Information System (INIS)

    Gomes, Rogerio dos Santos; Gomes, Joana D'Arc Ramos Lopes; Costa, Mara Lucia de Lara; Miranda, Marcia Valeria F.E. Sa

    2011-01-01

    The regulatory process in oil and gas well logging has shown the need for specific standard for the issuance of a license authorizing the use of sealed sources in well logging activities, in order to guarantee the quality of many factors from the point of view of radiation protection. Currently, have been used only generic radiation protection standards, but are not comprehensive or technically suitable for a well logging licensing purpose. The lack of a specific standard for licensing in radioactive well logging operations in Brazil, weakens the nuclear regulatory body in your aim of regulate and licensing the activity. This work establish, as main objective, a guideline for the future Brazilian radioprotection code in well logging operations, presenting relevant aspects not covered by generic radiation protection standards. (author)

  10. Radioprotection guidelines to the elaboration of a specific standard for the licensing of radioactive facilities on the practice of oil and gas well logging

    International Nuclear Information System (INIS)

    Gomes, Rogerio dos Santos; Gomes, Joana D'Arc Ramos Lopes; Costa, Mara Lucia de Lara; Miranda, Marcia Valeria F.E. Sa

    2011-01-01

    The regulatory process in oil and gas well logging has shown the need for specific standard for the issuance of a license authorizing the use of sealed sources in well logging activities, in order to guarantee the quality of many factors from the point of view of radiation protection. Currently, have been used only generic radiation protection standards, but are not comprehensive or technically suitable for a well logging licensing purpose. The lack of a specific standard for licensing in radioactive well logging operations in Brazil, weakens the nuclear regulatory body in your aim of regulate and licensing the activity. This work establish, as main objective, a guideline for the future Brazilian radioprotection code in well logging operations, presenting relevant aspects not covered by genetic radiation protection standards. (author)

  11. Successful Sampling Strategy Advances Laboratory Studies of NMR Logging in Unconsolidated Aquifers

    Science.gov (United States)

    Behroozmand, Ahmad A.; Knight, Rosemary; Müller-Petke, Mike; Auken, Esben; Barfod, Adrian A. S.; Ferré, Ty P. A.; Vilhelmsen, Troels N.; Johnson, Carole D.; Christiansen, Anders V.

    2017-11-01

    The nuclear magnetic resonance (NMR) technique has become popular in groundwater studies because it responds directly to the presence and mobility of water in a porous medium. There is a need to conduct laboratory experiments to aid in the development of NMR hydraulic conductivity models, as is typically done in the petroleum industry. However, the challenge has been obtaining high-quality laboratory samples from unconsolidated aquifers. At a study site in Denmark, we employed sonic drilling, which minimizes the disturbance of the surrounding material, and extracted twelve 7.6 cm diameter samples for laboratory measurements. We present a detailed comparison of the acquired laboratory and logging NMR data. The agreement observed between the laboratory and logging data suggests that the methodologies proposed in this study provide good conditions for studying NMR measurements of unconsolidated near-surface aquifers. Finally, we show how laboratory sample size and condition impact the NMR measurements.

  12. Static dictionaries on AC0 RAMs: query time (√log n/log log n) is necessary and sufficient

    DEFF Research Database (Denmark)

    Andersson, Arne; Miltersen, Peter Bro; Riis, Søren

    1996-01-01

    ) on the time for answering membership queries in a set of size n when reasonable space is used for the data structure storing the set; the upper bound can be obtained using O(n) space, and the lower bound holds even if we allow space 2polylog n. Several variations of this result are also obtained. Among others......, we show a tradeoff between time and circuit depth under the unit-cost assumption: any RAM instruction set which permits a linear space, constant query time solution to the static dictionary problem must have an instruction of depth Ω(log w/log log to), where w is the word size of the machine (and log...

  13. Logging a roadside stand to protect scenic values

    Science.gov (United States)

    Philip M. McDonald; Raymond V. Whiteley

    1972-01-01

    A case study on the Challenge Experimental Forest, California, demonstrated that logging along roadsides need not despoil roadside stands. Nearly every tree was "viewed" before marking. Because of the "special-care" procedures followed, combined logging and slash-disposal cost was about twice that of a single-tree selection cut.

  14. Condition and fate of logged forests in the Brazilian Amazon.

    Science.gov (United States)

    Gregory P. Asner; Eben N. Broadbent; Paulo J. C. Oliveira; Michael Keller; David E. Knapp; Jose N. M. Silva

    2006-01-01

    The long-term viability of a forest industry in the Amazon region of Brazil depends on the maintenance of adequate timber volume and growth in healthy forests. Using extensive high-resolution satellite analyses, we studied the forest damage caused by recent logging operations and the likelihood that logged forests would be cleared within 4 years after timber harvest....

  15. Veneer-log production and receipts, North Central Region, 1976.

    Science.gov (United States)

    James E. Blyth; Jerold T. Hahn

    1978-01-01

    Shows 1976 veneer-log production and receipts by species in the Lake States (Michigan, Minnesota, and Wisconsin) and in the Central States (Illinois, Indiana, Iowa, and Missouri). Comparisons are made with similar data for 1974. Includes tables showing veneer-log production and receipts (for selected years) since 1946 in the Lake States and since 1956 in the Central...

  16. Veneer-log production and receipts, North Central Region, 1974.

    Science.gov (United States)

    James E. Blyth; Jerold T. Hahn

    1976-01-01

    Shows 1974 veneer-log production and receipts by species in the Lake States (Michigan, Minnesota, and Wisconsin) and in the Central States (Illinois, Indiana, Iowa, and Missouri). Comparisons are made with similar data for 1972. Includes tables showing veneer-log production and receipts (for selected years) since 1946 in the Lake States and since 1956 in the Central...

  17. A selective logging mechanism for hardware transactional memory systems

    OpenAIRE

    Lupon Navazo, Marc; Magklis, Grigorios; González Colás, Antonio María

    2011-01-01

    Log-based Hardware Transactional Memory (HTM) systems offer an elegant solution to handle speculative data that overflow transactional L1 caches. By keeping the pre-transactional values on a software-resident log, speculative values can be safely moved across the memory hierarchy, without requiring expensive searches on L1 misses or commits.

  18. Teaching an Old Log New Tricks with Machine Learning.

    Science.gov (United States)

    Schnell, Krista; Puri, Colin; Mahler, Paul; Dukatz, Carl

    2014-03-01

    To most people, the log file would not be considered an exciting area in technology today. However, these relatively benign, slowly growing data sources can drive large business transformations when combined with modern-day analytics. Accenture Technology Labs has built a new framework that helps to expand existing vendor solutions to create new methods of gaining insights from these benevolent information springs. This framework provides a systematic and effective machine-learning mechanism to understand, analyze, and visualize heterogeneous log files. These techniques enable an automated approach to analyzing log content in real time, learning relevant behaviors, and creating actionable insights applicable in traditionally reactive situations. Using this approach, companies can now tap into a wealth of knowledge residing in log file data that is currently being collected but underutilized because of its overwhelming variety and volume. By using log files as an important data input into the larger enterprise data supply chain, businesses have the opportunity to enhance their current operational log management solution and generate entirely new business insights-no longer limited to the realm of reactive IT management, but extending from proactive product improvement to defense from attacks. As we will discuss, this solution has immediate relevance in the telecommunications and security industries. However, the most forward-looking companies can take it even further. How? By thinking beyond the log file and applying the same machine-learning framework to other log file use cases (including logistics, social media, and consumer behavior) and any other transactional data source.

  19. The log-linear return approximation, bubbles, and predictability

    DEFF Research Database (Denmark)

    Engsted, Tom; Pedersen, Thomas Quistgaard; Tanggaard, Carsten

    We study in detail the log-linear return approximation introduced by Campbell and Shiller (1988a). First, we derive an upper bound for the mean approximation error, given stationarity of the log dividendprice ratio. Next, we simulate various rational bubbles which have explosive conditional expec...

  20. The Log-Linear Return Approximation, Bubbles, and Predictability

    DEFF Research Database (Denmark)

    Engsted, Tom; Pedersen, Thomas Quistgaard; Tanggaard, Carsten

    2012-01-01

    We study in detail the log-linear return approximation introduced by Campbell and Shiller (1988a). First, we derive an upper bound for the mean approximation error, given stationarity of the log dividend-price ratio. Next, we simulate various rational bubbles which have explosive conditional expe...

  1. Predictive models of forest logging residues of Triplochiton ...

    African Journals Online (AJOL)

    The model developed indicated that logarithmic functions performed better than other form of equation. The findings of this study revealed that there is significant logging residues left to waste in the forest after timber harvest and quantifying this logging residue in terms of biomass model can serve as management tools in ...

  2. Secure Audit Logging with Tamper-Resistant Hardware

    NARCIS (Netherlands)

    Chong, C.N.; Peng, Z.; Peng, Z.; Hartel, Pieter H.; Gritzalis, D.; De Capitani di Vimercati, S.; Katsikas, S.K.; Samarati, P.

    Secure perimeter schemes (e.g. DRM) and tracing traitor schemes (e.g. watermarking, audit logging) strive to mitigate the problems of content escaping the control of the rights holder. Secure audit logging records the user's actions on content and enables detection of some forms of tampering with

  3. Ubiquitous Learning Project Using Life-Logging Technology in Japan

    Science.gov (United States)

    Ogata, Hiroaki; Hou, Bin; Li, Mengmeng; Uosaki, Noriko; Mouri, Kosuke; Liu, Songran

    2014-01-01

    A Ubiquitous Learning Log (ULL) is defined as a digital record of what a learner has learned in daily life using ubiquitous computing technologies. In this paper, a project which developed a system called SCROLL (System for Capturing and Reusing Of Learning Log) is presented. The aim of developing SCROLL is to help learners record, organize,…

  4. 14 CFR 125.407 - Maintenance log: Airplanes.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintenance log: Airplanes. 125.407 Section... OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6... Maintenance log: Airplanes. (a) Each person who takes corrective action or defers action concerning a reported...

  5. Ontology-driven extraction of event logs from relational databases

    NARCIS (Netherlands)

    Calvanese, Diego; Montali, Marco; Syamsiyah, Alifah; van der Aalst, Wil M P; Reichert, M.; Reijers, H.A.

    2015-01-01

    Process mining is an emerging discipline whose aim is to discover, monitor and improve real processes by extracting knowledge from event logs representing actual process executions in a given organizational setting. In this light, it can be applied only if faithful event logs, adhering to accepted

  6. Prediction of Log "P": ALOGPS Application in Medicinal Chemistry Education

    Science.gov (United States)

    Kujawski, Jacek; Bernard, Marek K.; Janusz, Anna; Kuzma, Weronika

    2012-01-01

    Molecular hydrophobicity (lipophilicity), usually quantified as log "P" where "P" is the partition coefficient, is an important molecular characteristic in medicinal chemistry and drug design. The log "P" coefficient is one of the principal parameters for the estimation of lipophilicity of chemical compounds and pharmacokinetic properties. The…

  7. Log-periodic dipole antenna with low cross-polarization

    DEFF Research Database (Denmark)

    Pivnenko, Sergey

    2006-01-01

    In this work, log-periodic antennas with improved cross-polarization level were studied. It was found that some modifications of the traditional design lead to an essential improvement of the co-to-cross polarization ratio up to 40 dB. An improved design of a log-periodic dipole antenna with low...

  8. 21 CFR 211.182 - Equipment cleaning and use log.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Equipment cleaning and use log. 211.182 Section 211.182 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Reports § 211.182 Equipment cleaning and use log. A written record of major equipment cleaning...

  9. Logging residues under different stand and harvesting conditions, Rocky Mountains

    Science.gov (United States)

    Robert E. Benson; Cameron M. Johnston

    1976-01-01

    Volume and characteristics of logging residues from 34 harvest areas are presented. Clearcuts and partial cuts logged to conventional utilization levels and to close utilization levels are included. Residue volumes ranged from almost 3, 600 ft3 /acre of wood 3-inches-plus down to about 550 ft3 /acre, depending on treatment. More than 60 percent of the residues were...

  10. Fates of trees damaged by logging in Amazonian Bolivia

    NARCIS (Netherlands)

    Shenkin, A.; Bolker, B.; Peña Claros, M.; Licona, J.C.; Putz, F.E.

    2015-01-01

    Estimation of carbon losses from trees felled and incidentally-killed during selective logging of tropical forests is relatively straightforward and well-documented, but less is known about the fates of collaterally-damaged trees that initially survive. Tree response to logging damage is an

  11. Inversion of a lateral log using neural networks

    International Nuclear Information System (INIS)

    Garcia, G.; Whitman, W.W.

    1992-01-01

    In this paper a technique using neural networks is demonstrated for the inversion of a lateral log. The lateral log is simulated by a finite difference method which in turn is used as an input to a backpropagation neural network. An initial guess earth model is generated from the neural network, which is then input to a Marquardt inversion. The neural network reacts to gross and subtle data features in actual logs and produces a response inferred from the knowledge stored in the network during a training process. The neural network inversion of lateral logs is tested on synthetic and field data. Tests using field data resulted in a final earth model whose simulated lateral is in good agreement with the actual log data

  12. Toward an Automated Labeling of Event Log Attributes

    DEFF Research Database (Denmark)

    Abbad Andaloussi, Amine; Burattin, Andrea; Weber, Barbara

    2018-01-01

    information systems often do not comply with the required maturity level, since they lack the notion of process instance, also referred in process mining as “case id”. Without a proper identification of the case id attribute in log files, the outcome of process mining algorithms is unpredictable. This paper...... proposes a new approach that aims to overcome this challenge by automatically inferring the case id attribute from log files. The approach has been implemented as a ProM plugin and evaluated with several real-world event logs. The results demonstrate a high accuracy in inferring the case id attribute.......Process mining aims at exploring the data produced by executable business processes to mine the underlying control-flow and dataflow. Most of the process mining algorithms assume the existence of an event log with a certain maturity level. Unfortunately, the logs provided by process unaware...

  13. Rock mass characterization for Copenhagen Metro using face logs

    DEFF Research Database (Denmark)

    Hansen, Sanne Louise; Galsgaard, Jens; Foged, Niels Nielsen

    2015-01-01

    An extension of the existing Metro in central Copenhagen is currently under construction. We present a comparison of the different field logging techniques available from a large number of borehole logs and face logs carried out during the construction in cooperation with the constructor and client......, describing rock mass characteristics using detailed face logging with geological description and recording of induration and fracturing, giving a field RQD value during excavation, combined with televiewer logs, when available, has shown to be a valuable tool for rock mass characterization compared......’s representatives, which illustrate and approve the applied methods. The new ‘Cityringen’ Metro will consist of two 16 km single track tunnels, with 17 stations and 3 construction and ventilation shafts. The geological ground conditions are dominated by glacial and postglacial deposits overlying Paleocene Greensand...

  14. Log-concavity property for some well-known distributions

    Directory of Open Access Journals (Sweden)

    G. R. Mohtashami Borzadaran

    2011-12-01

    Full Text Available Interesting properties and propositions, in many branches of science such as economics have been obtained according to the property of cumulative distribution function of a random variable as a concave function. Caplin and Nalebuff (1988,1989, Bagnoli and Khanna (1989 and Bagnoli and Bergstrom (1989 , 1989, 2005 have discussed the log-concavity property of probability distributions and their applications, especially in economics. Log-concavity concerns twice differentiable real-valued function g whose domain is an interval on extended real line. g as a function is said to be log-concave on the interval (a,b if the function ln(g is a concave function on (a,b. Log-concavity of g on (a,b is equivalent to g'/g being monotone decreasing on (a,b or (ln(g" 6] have obtained log-concavity for distributions such as normal, logistic, extreme-value, exponential, Laplace, Weibull, power function, uniform, gamma, beta, Pareto, log-normal, Student's t, Cauchy and F distributions. We have discussed and introduced the continuous versions of the Pearson family, also found the log-concavity for this family in general cases, and then obtained the log-concavity property for each distribution that is a member of Pearson family. For the Burr family these cases have been calculated, even for each distribution that belongs to Burr family. Also, log-concavity results for distributions such as generalized gamma distributions, Feller-Pareto distributions, generalized Inverse Gaussian distributions and generalized Log-normal distributions have been obtained.

  15. Nuclear techniques in oil and gas exploration and production

    International Nuclear Information System (INIS)

    Caldwell, R.L.; Mills, W.R. Jr.; Orr, W.L.; Allen, L.S.

    1977-01-01

    A review is given of some of the most significant new developments that have occurred during the past three years in the area of nuclear techniques applied to the exploration for and production of oil and gas deposits. Experimental and theoretical studies have been carried out aimed at improving pulsed neutron logging tools and upgrading interpretation of data from such tools. Pulsed neutron borehole generators and gamma-ray spectroscopy have been combined in carbon/oxygen logging to provide a means of determining formation oil saturation in cased holes that is independent of water salinity. Use of pulsed neutron logs in the log-inject-log technique has been tested and evaluated in several field studies. The combination of a gamma-gamma density log and a borehole gravimeter has been used to detect economically important gas accumulations at distances from a borehole that are well beyond the depth of investigation of conventional logging techniques. The depths of investigation of several commercial nuclear logging tools have been studied in laboratory investigations. Possible geological applications of natural gamma-ray spectral logs have been investigated through the study of large sample suites and in specific field applications. The extensive use of digital recording of logging data and well-site analysis by minicomputer are expected to have a significant influence on future logging programmes and logging sonde designs. The present status of stable isotope geochemistry and radioactive tracer surveys is reviewed. (author)

  16. Influence of borehole-eccentred tools on wireline and logging-while-drilling sonic logging measurements

    KAUST Repository

    Pardo, David

    2013-02-13

    We describe a numerical study to quantify the influence of tool-eccentricity on wireline (WL) and logging-while-drilling (LWD) sonic logging measurements. Simulations are performed with a height-polynomial-adaptive (hp) Fourier finite-element method that delivers highly accurate solutions of linear visco-elasto-acoustic problems in the frequency domain. The analysis focuses on WL instruments equipped with monopole or dipole sources and LWD instruments with monopole excitation. Analysis of the main propagation modes obtained from frequency dispersion curves indicates that the additional high-order modes arising as a result of borehole-eccentricity interfere with the main modes (i.e., Stoneley, pseudo-Rayleigh and flexural). This often modifies (decreases) the estimation of shear and compressional formation velocities, which should be corrected (increased) to account for borehole-eccentricity effects. Undesired interferences between different modes can occur at different frequencies depending upon the properties of the formation and fluid annulus size, which may difficult the estimation of the formation velocities. © 2013 European Association of Geoscientists & Engineers.

  17. Lithologic log and interpretation of instrument logs NURE project, Carson Sink, Nevada, borehole

    International Nuclear Information System (INIS)

    Horton, R.C.

    1978-04-01

    No uranium mineralization was penetrated by the drilling. The uranium content of the rock units are within the usual range for unmineralized rocks of the types penetrated. Although the instrument logs indicated ample porosity in the sedimentary section, drill-stem tests in the intervals 699 to 722 ft, 3,692 to 3,734 ft, and 3,920 to 3,995 ft failed to recover any formation fluid. The instrument logs generally indicated low porosity and permeability in the volcanic rocks. The low permeability may have prohibited the circulation of ground water and possible supergene enrichment. The Carson Sink is a closed basin and all water is lost by evaporation, although there may be minor subsurface interbasin transfer. As the basin subsided dense connate water (brines) may have been trapped within the sediments making circulation of less dense water impossible. At present, nonsaline water is found only at shallow depths and is underlain by saline water. The hydrologic regime of the basin is complex and general assumptions should be made with care. Detailed analysis of hydrologic data may reveal zones of deep circulation. Reducing conditions, as evidenced by thin beds of organic rich material and pyrite, are present at depth. However, the unconsolidated sediments are young (Pleistocene to Recent) and perhaps too youthful for substantial mineralization to have occurred. No further deep drilling is recommended until the complex prehistoric hydrologic regime is studied. The study should include the geologic structural history of the basin and influence of Pleistocene and earlier pluvial cycles

  18. Fast neutron (14 MeV) attenuation analysis in saturated core samples and its application in well logging

    International Nuclear Information System (INIS)

    Amin Attarzadeh; Mohammad Kamal Ghassem Al Askari; Tagy Bayat

    2009-01-01

    To introduce the application of nuclear logging, it is appropriate to provide a motivation for the use of nuclear measurement techniques in well logging. Importance aspects of the geological sciences are for instance grain and porosity structure and porosity volume of the rocks, as well as the transport properties of a fluid in the porous media. Nuclear measurements are, as a rule non-intrusive. Namely, a measurement does not destroy the sample, and it does not interfere with the process to be measured. Also, non- intrusive measurements are often much faster than the radiation methods, and can also be applied in field measurements. A common type of nuclear measurement employs neutron irradiation. It is powerful technique for geophysical analysis. In this research we illustrate the detail of this technique and it's applications to well logging and oil industry. Experiments have been performed to investigate the possibilities of using neutron attenuation measurements to determine water and oil content of rock sample. A beam of 14 MeV neutrons produced by a 150 KV neutron generator was attenuated by different samples and subsequently detected with plastic scintillators NE102 (Fast counter). Each sample was saturated with water and oil. The difference in neutron attenuation between dry and wet samples was compared with the fluid content determined by mass balance of the sample. In this experiment we were able to determine 3% of humidity in standard sample model (SiO 2 ) and estimate porosity in geological samples when saturated with different fluids. (Author)

  19. Audits by registrants authorized for use of radiation sources in well logging

    International Nuclear Information System (INIS)

    Jordan, O.D.

    1999-01-01

    An audit was carried out by the Argentine Nuclear Regulatory Authority to verify regulations and safe working procedures compliance by registrants authorized for use of radiation sources in well logging. A task force based on four inspection teams was organized. The audit was carried out at registrant's premises (equipment storage facilities) simultaneously. The evaluation was based on a system allowing a fast qualification of both, potential problems identified and their solutions. The results show that 95 % of the inspected locations were classified under the 'acceptable', 'good' and 'very good' headings. (author)

  20. Review of the Czubek--Jonas gamma-log program

    International Nuclear Information System (INIS)

    Matthews, M.

    1978-11-01

    Several gamma-ray logs were computer processed using the Czubek--Jones and DOE's MDDAT gamma-log programs. Both of these programs convert counts per second from the gamma-ray logs to percent eU 3 O 8 . The results of these programs were compared to each other and to the core analysis (percent U 3 O 8 ) of the logged boreholes. The two gamma-log programs produced similar results. The core analysis did not compare favorably with the results of either gamma-log program. This unfavorable comparison is probably due to an incorrect assumption of secular equilibrium for the ore surrounding the boreholes. The Czubek--Jonas program requires a knowledge of the linear attenuation coefficient of the rocks surrounding a borehole. This limits the usefulness of the program because this coefficient is generally not known and varies for different gamma-ray energies. It is recommended that the MDDAT program continue to be used for estimating the grade (percent eU 3 O 8 ) from gamma-log data and not be replaced by the Czubek--Jonas program

  1. Dual detector neutron lifetime log: theory and practical applications

    International Nuclear Information System (INIS)

    Serpas, C.J.; Wichmann, P.A.; Fertl, W.H.; DeVries, M.R.; Rndall, R.R.

    1977-01-01

    The Neutron Lifetime Log instrumentation has continued to evolve and now is equipped with dual detectors for increased ease in gas detection and also a ratio response for a simultaneous porosity determination. A good deal of experimentation was involved to minimize both lithology and salinity effects on the porosity indication. This paper contains a discussion of the theory and concepts related to the application of the Dual Detector Neutron Lifetime Log (DNLL). It is important to note that with these advances the recording of thermal neutron capture cross section (Σ) remains consistent with the past measurements of earlier generations of instruments as the most accurate determination of this parameter. A number of field examples of the newly logged results are shown. These field cases include Dual Detector NLL's run thru the drill strings of highly deviated holes when difficulties were encountered in getting conventional open hole logs to bottom, logs thru open perforations and hot radioactive zones, comparisons of the large and small diameter instruments, logs with anomalous fluids in the annulus, logs thru multiple casing strings, and a number of other examples

  2. Numerical simulation of responses for cased-hole density logging

    International Nuclear Information System (INIS)

    Wu, Wensheng; Fu, Yaping; Niu, Wei

    2013-01-01

    Stabilizing or stimulating oil production in old oil fields requires density logging in cased holes where open-hole logging data are either missing or of bad quality. However, measured values from cased-hole density logging are more severely influenced by factors such as fluid, casing, cement sheath and the outer diameter of the open-hole well compared with those from open-hole logging. To correctly apply the cased-hole formation density logging data, one must eliminate these influences on the measured values and study the characteristics of how the cased-hole density logging instrument responds to these factors. In this paper, a Monte Carlo numerical simulation technique was used to calculate the responses of the far detector of a cased-hole density logging instrument to in-hole fluid, casing wall thickness, cement sheath density and the formation and thus to obtain influence rules and response coefficients. The obtained response of the detector is a function of in-hole liquid, casing wall thickness, the casing's outer diameter, cement sheath density, open-hole well diameter and formation density. The ratio of the counting rate of the detector in the calibration well to that in the measurement well was used to get a fairly simple detector response equation and the coefficients in the equation are easy to acquire. These provide a new way of calculating cased-hole density through forward modelling methods. (paper)

  3. Extracting the Textual and Temporal Structure of Supercomputing Logs

    Energy Technology Data Exchange (ETDEWEB)

    Jain, S; Singh, I; Chandra, A; Zhang, Z; Bronevetsky, G

    2009-05-26

    Supercomputers are prone to frequent faults that adversely affect their performance, reliability and functionality. System logs collected on these systems are a valuable resource of information about their operational status and health. However, their massive size, complexity, and lack of standard format makes it difficult to automatically extract information that can be used to improve system management. In this work we propose a novel method to succinctly represent the contents of supercomputing logs, by using textual clustering to automatically find the syntactic structures of log messages. This information is used to automatically classify messages into semantic groups via an online clustering algorithm. Further, we describe a methodology for using the temporal proximity between groups of log messages to identify correlated events in the system. We apply our proposed methods to two large, publicly available supercomputing logs and show that our technique features nearly perfect accuracy for online log-classification and extracts meaningful structural and temporal message patterns that can be used to improve the accuracy of other log analysis techniques.

  4. Construction and validation of a Tamil logMAR chart.

    Science.gov (United States)

    Varadharajan, Srinivasa; Srinivasan, Krithica; Kumaresan, Brindha

    2009-09-01

    To design, construct and validate a new Tamil logMAR visual acuity chart based on current recommendations. Ten Tamil letters of equal legibility were identified experimentally and were used in the chart. Two charts, one internally illuminated and one externally illuminated, were constructed for testing at 4 m distance. The repeatability of the two charts was tested. For validation, the two charts were compared with a standard English logMAR chart (ETDRS). When compared to the ETDRS chart, a difference of 0.06 +/- 0.07 and 0.07 +/- 0.07 logMAR was found for the internally and externally illuminated charts respectively. Limits of agreement between the internally illuminated Tamil logMAR chart and ETDRS chart were found to be (-0.08, 0.19), and (-0.07, 0.20) for the externally illuminated chart. The test - retest results showed a difference of 0.02 +/- 0.04 and 0.02 +/- 0.06 logMAR for the internally and externally illuminated charts respectively. Limits of agreement for repeated measurements for the internally illuminated Tamil logMAR chart were found to be (-0.06, 0.10), and (-0.10, 0.14) for the externally illuminated chart. The newly constructed Tamil logMAR charts have good repeatability. The difference in visual acuity scores between the newly constructed Tamil logMAR chart and the standard English logMAR chart was within acceptable limits. This new chart can be used for measuring visual acuity in the literate Tamil population.

  5. Geothermal well log interpretation state of the art. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1980-01-01

    An in-depth study of the state of the art in Geothermal Well Log Interpretation has been made encompassing case histories, technical papers, computerized literature searches, and actual processing of geothermal wells from New Mexico, Idaho, and California. A classification scheme of geothermal reservoir types was defined which distinguishes fluid phase and temperature, lithology, geologic province, pore geometry, salinity, and fluid chemistry. Major deficiencies of Geothermal Well Log Interpretation are defined and discussed with recommendations of possible solutions or research for solutions. The Geothermal Well Log Interpretation study and report has concentrated primarily on Western US reservoirs. Geopressured geothermal reservoirs are not considered.

  6. Application of computer data processing of well logging in Azerbaijan

    International Nuclear Information System (INIS)

    Vorob'ev, Yu.A.; Shilov, G.Ya.; Samedova, A.S.

    1989-01-01

    Transition from the mannal quantitative interpretation of materials of well-logging study (WLS) to application of computer in production association (PA) Azneftegeologiya is described. WLS materials were processed manually in PA till 1986. Later on interpretation was conducted with the use of computer in order to determine clayiness, porosity, oil and gas saturation, fluid of strata. Examples of presentation of results of computer interpretation of WLS data (including gamma-logging and neutron-gamma-logging) for determining porosity and oil saturation of sandy mudrocks are given

  7. Screening efficacy of a simplified logMAR chart

    Directory of Open Access Journals (Sweden)

    Naganathan Muthuramalingam

    2016-04-01

    Aim: This study evaluates the efficacy of a simplified logMAR chart, designed for VA testing over the conventional Snellen chart, in a school-based vision-screening programme. Methods: We designed a simplified logMAR chart by employing the principles of the Early Treatment Diabetic Retinopathy Study (ETDRS chart in terms of logarithmic letter size progression, inter-letter spacing, and inter-line spacing. Once the simplified logMAR chart was validated by students in the Elite school vision-screening programme, we set out to test the chart in 88 primary and middle schools in the Tiruporur block of Kancheepuram district in Tamil Nadu. One school teacher in each school was trained to screen a cross-sectional population of 10 354 primary and secondary school children (girls: 5488; boys: 4866 for VA deficits using a new, simplified logMAR algorithm. An experienced paediatric optometrist was recruited to validate the screening methods and technique used by the teachers to collect the data. Results: The optometrist screened a subset of 1300 school children from the total sample. The optometrist provided the professional insights needed to validate the clinical efficacy of the simplified logMAR algorithm and verified the reliability of the data collected by the teachers. The mean age of children sampled for validation was 8.6 years (range: 9–14 years. The sensitivity and the specificity of the simplified logMAR chart when compared to the standard logMAR chart were found to be 95% and 98%, respectively. Kappa value was 0.97. Sensitivity of the teachers’ screening was 66.63% (95% confidence interval [CI]: 52.73–77.02 and the specificity was 98.33% (95% CI: 97.49–98.95. Testing of VA was done under substandard illumination levels in 87% of the population. A total of 10 354 children were screened, 425 of whom were found to have some form of visual and/or ocular defect that was identified by the teacher or optometrist. Conclusion: The simplified logMAR testing algorithm

  8. Perfil logístico del sector cemento en Colombia

    OpenAIRE

    Hernández Calderón, Miguel Ángel; Nieves de la Hoz, Celia Elena

    2015-01-01

    Este proyecto caracteriza la logística del sector cemento en Colombia al identificar y describir los principales actores, procesos y materiales involucrados en la cadena de suministros del sector. Este documento compila la información logística relevante para la producción de cemento en Colombia. Esta información se obtuvo sintetizando estudios y reportes acerca de las prácticas logísticas y las condiciones en las que éstas se desarrollan. Adicionalmente se realizaron visitas empresariales en...

  9. Development of interpretation models for PFN uranium log analysis

    International Nuclear Information System (INIS)

    Barnard, R.W.

    1980-11-01

    This report presents the models for interpretation of borehole logs for the PFN (Prompt Fission Neutron) uranium logging system. Two models have been developed, the counts-ratio model and the counts/dieaway model. Both are empirically developed, but can be related to the theoretical bases for PFN analysis. The models try to correct for the effects of external factors (such as probe or formation parameters) in the calculation of uranium grade. The theoretical bases and calculational techniques for estimating uranium concentration from raw PFN data and other parameters are discussed. Examples and discussions of borehole logs are included

  10. Quantifying diagnostic performance: The log odds method as a practical option

    International Nuclear Information System (INIS)

    Haslam, Maxine; Manning, David

    2006-01-01

    Purpose: To investigate the most practical option available when statistically analysing small sample size studies. Method: The log odds ratio was applied to a study which took a retrospective approach and involved 50 patients who had undergone a ventilation and perfusion scan in the period between 01 January 2002 and 31 December 2002. Radiology reports and the patients' medical records were obtained, so that the clinical indications for the examination and the patients' medical history could be transferred onto the report form. Four radiographers who are routinely rotated into the Nuclear Medicine Department independently reported the same 50 ventilations and perfusion scans under identical conditions to the reporting radiologist. Results: Taking the radiologist reports as the gold standard the radiographers had an accuracy rate of 78%. The radiographers recorded an average sensitivity value of 94% and specificity value of 63%, with an A z reading of 0.71. Conclusion: As the sample size was too small for a receiver operating characteristic (ROC) curve to be drawn, the log odds ratio provided a value, which represents an area under the receiver operating characteristic (ROC) curve, which in turn ensured the results were statistically reliable. The log odds ratio enables researchers to carry out small-scale research without harbouring the data collected by unreliable analysis

  11. A Field Study of NMR Logging to Quantify Petroleum Contamination in Subsurface Sediments

    Science.gov (United States)

    Fay, E. L.; Knight, R. J.; Grunewald, E. D.

    2016-12-01

    Nuclear magnetic resonance (NMR) measurements are directly sensitive to hydrogen-bearing fluids including water and petroleum products. NMR logging tools can be used to detect and quantify petroleum hydrocarbon contamination in the sediments surrounding a well or borehole. An advantage of the NMR method is that data can be collected in both cased and uncased holes. In order to estimate the volume of in-situ hydrocarbon, there must be sufficient contrast between either the relaxation times (T2) or the diffusion coefficients (D) of water and the contaminant. In a field study conducted in Pine Ridge, South Dakota, NMR logging measurements were used to investigate an area of hydrocarbon contamination from leaking underground storage tanks. A contaminant sample recovered from a monitoring well at the site was found to be consistent with a mixture of gasoline and diesel fuel. NMR measurements were collected in two PVC-cased monitoring wells; D and T2 measurements were used together to detect and quantify contaminant in the sediments above and below the water table at both of the wells. While the contrast in D between the fluids was found to be inadequate for fluid typing, the T2 contrast between the contaminant and water in silt enabled the estimation of the water and contaminant volumes. This study shows that NMR logging can be used to detect and quantify in-situ contamination, but also highlights the importance of sediment and contaminant properties that lead to a sufficiently large contrast in T2 or D.

  12. An innovative OSCE clinical log station: a quantitative study of its influence on Log use by medical students

    Directory of Open Access Journals (Sweden)

    Hudson Judith N

    2012-11-01

    Full Text Available Abstract Background A Clinical Log was introduced as part of a medical student learning portfolio, aiming to develop a habit of critical reflection while learning was taking place, and provide feedback to students and the institution on learning progress. It was designed as a longitudinal self-directed structured record of student learning events, with reflection on these for personal and professional development, and actions planned or taken for learning. As incentive was needed to encourage student engagement, an innovative Clinical Log station was introduced in the OSCE, an assessment format with established acceptance at the School. This study questions: How does an OSCE Clinical Log station influence Log use by students? Methods The Log station was introduced into the formative, and subsequent summative, OSCEs with careful attention to student and assessor training, marking rubrics and the standard setting procedure. The scoring process sought evidence of educational use of the log, and an ability to present and reflect on key learning issues in a concise and coherent manner. Results Analysis of the first cohort’s Log use over the four-year course (quantified as number of patient visits entered by all students revealed limited initial use. Usage was stimulated after introduction of the Log station early in third year, with some improvement during the subsequent year-long integrated community-based clerkship. Student reflection, quantified by the mean number of characters in the ‘reflection’ fields per entry, peaked just prior to the final OSCE (mid-Year 4. Following this, very few students continued to enter and reflect on clinical experience using the Log. Conclusion While the current study suggested that we can’t assume students will self-reflect unless such an activity is included in an assessment, ongoing work has focused on building learner and faculty confidence in the value of self-reflection as part of being a competent

  13. Methods for processing of pulsed neutron logging data

    International Nuclear Information System (INIS)

    Iskenderov, V.G.

    1975-01-01

    Conditions were examined for calculating the lifetime of thermal neutrons in neutron-neutron logging by selecting optimum values for the time lag. The dispersion and mean square error of the calculated lifetime values for thermal neutrons are evaluated

  14. Logging cuts the functional importance of invertebrates in tropical rainforest.

    Science.gov (United States)

    Ewers, Robert M; Boyle, Michael J W; Gleave, Rosalind A; Plowman, Nichola S; Benedick, Suzan; Bernard, Henry; Bishop, Tom R; Bakhtiar, Effendi Y; Chey, Vun Khen; Chung, Arthur Y C; Davies, Richard G; Edwards, David P; Eggleton, Paul; Fayle, Tom M; Hardwick, Stephen R; Homathevi, Rahman; Kitching, Roger L; Khoo, Min Sheng; Luke, Sarah H; March, Joshua J; Nilus, Reuben; Pfeifer, Marion; Rao, Sri V; Sharp, Adam C; Snaddon, Jake L; Stork, Nigel E; Struebig, Matthew J; Wearn, Oliver R; Yusah, Kalsum M; Turner, Edgar C

    2015-04-13

    Invertebrates are dominant species in primary tropical rainforests, where their abundance and diversity contributes to the functioning and resilience of these globally important ecosystems. However, more than one-third of tropical forests have been logged, with dramatic impacts on rainforest biodiversity that may disrupt key ecosystem processes. We find that the contribution of invertebrates to three ecosystem processes operating at three trophic levels (litter decomposition, seed predation and removal, and invertebrate predation) is reduced by up to one-half following logging. These changes are associated with decreased abundance of key functional groups of termites, ants, beetles and earthworms, and an increase in the abundance of small mammals, amphibians and insectivorous birds in logged relative to primary forest. Our results suggest that ecosystem processes themselves have considerable resilience to logging, but the consistent decline of invertebrate functional importance is indicative of a human-induced shift in how these ecological processes operate in tropical rainforests.

  15. Logging cuts the functional importance of invertebrates in tropical rainforest

    Science.gov (United States)

    Ewers, Robert M.; Boyle, Michael J. W.; Gleave, Rosalind A.; Plowman, Nichola S.; Benedick, Suzan; Bernard, Henry; Bishop, Tom R.; Bakhtiar, Effendi Y.; Chey, Vun Khen; Chung, Arthur Y. C.; Davies, Richard G.; Edwards, David P.; Eggleton, Paul; Fayle, Tom M.; Hardwick, Stephen R.; Homathevi, Rahman; Kitching, Roger L.; Khoo, Min Sheng; Luke, Sarah H.; March, Joshua J.; Nilus, Reuben; Pfeifer, Marion; Rao, Sri V.; Sharp, Adam C.; Snaddon, Jake L.; Stork, Nigel E.; Struebig, Matthew J.; Wearn, Oliver R.; Yusah, Kalsum M.; Turner, Edgar C.

    2015-01-01

    Invertebrates are dominant species in primary tropical rainforests, where their abundance and diversity contributes to the functioning and resilience of these globally important ecosystems. However, more than one-third of tropical forests have been logged, with dramatic impacts on rainforest biodiversity that may disrupt key ecosystem processes. We find that the contribution of invertebrates to three ecosystem processes operating at three trophic levels (litter decomposition, seed predation and removal, and invertebrate predation) is reduced by up to one-half following logging. These changes are associated with decreased abundance of key functional groups of termites, ants, beetles and earthworms, and an increase in the abundance of small mammals, amphibians and insectivorous birds in logged relative to primary forest. Our results suggest that ecosystem processes themselves have considerable resilience to logging, but the consistent decline of invertebrate functional importance is indicative of a human-induced shift in how these ecological processes operate in tropical rainforests. PMID:25865801

  16. Log-Normal Turbulence Dissipation in Global Ocean Models

    Science.gov (United States)

    Pearson, Brodie; Fox-Kemper, Baylor

    2018-03-01

    Data from turbulent numerical simulations of the global ocean demonstrate that the dissipation of kinetic energy obeys a nearly log-normal distribution even at large horizontal scales O (10 km ) . As the horizontal scales of resolved turbulence are larger than the ocean is deep, the Kolmogorov-Yaglom theory for intermittency in 3D homogeneous, isotropic turbulence cannot apply; instead, the down-scale potential enstrophy cascade of quasigeostrophic turbulence should. Yet, energy dissipation obeys approximate log-normality—robustly across depths, seasons, regions, and subgrid schemes. The distribution parameters, skewness and kurtosis, show small systematic departures from log-normality with depth and subgrid friction schemes. Log-normality suggests that a few high-dissipation locations dominate the integrated energy and enstrophy budgets, which should be taken into account when making inferences from simplified models and inferring global energy budgets from sparse observations.

  17. Irrationality measures of $\\log 2$ and $\\pi/\\sqrt{3}$

    OpenAIRE

    Brisebarre, Nicolas

    2001-01-01

    Using a class of polynomials that generalizes Legendre polynomials, we unify previous works of E. A. Rukhadze, A. K. Dubitskas, M. Hata, D. V. and G. V. Chudnovsky about irrationality measures of $\\log 2$ and $\\pi/\\sqrt{3}$

  18. Logging technique for assaying for uranium in rocks

    International Nuclear Information System (INIS)

    Givens, W.W.

    1973-01-01

    A uranium exploration technique is described for determining the uranium content of a formation traversed by borehole. A delayed fission neutron assay log is obtained by irradiating the formation with repetitive bursts of fast neutrons and detecting delayed neutrons resulting from neutron fission of uranium at time intervals between the fast neutron bursts and after dissipation of the neutrons originating in the bursts. In addition, a response log is obtained by irradiating the formation with a source of fast neutrons whereby the neutrons from this source are moderated in the formation to lower energy levels and are subject to absorption. Secondary radiation attendant to these lower energy neutrons is recorded in order to obtain a log representative of the response of the formation to moderation and absorption of the neutrons. The two logs thus obtained are correlated in order to determine a corrected value of uranium content of the formation. (author)

  19. Cross-system log file analysis for hypothesis testing

    NARCIS (Netherlands)

    Glahn, Christian

    2008-01-01

    Glahn, C. (2008). Cross-system log file analysis for hypothesis testing. Presented at Empowering Learners for Lifelong Competence Development: pedagogical, organisational and technological issues. 4th TENCompetence Open Workshop. April, 10, 2008, Madrid, Spain.

  20. Modelling discontinuous well log signal to identify lithological ...

    Indian Academy of Sciences (India)

    1Indian School of Mines (ISM), Dhanbad 826 004, India. ... new wavelet transform-based algorithm to model the abrupt discontinuous changes from well log data by taking care of ...... the 11th ACM International Conference on Multimedia,.

  1. Assessment of procurement systems for unutilized logging residues ...

    African Journals Online (AJOL)

    ... in the forest after clear-cutting operation with cutto- length harvesting method. ... as system-2 can be preferable for the initial supply chain configuration in Turkey. ... Key words: logging residue, forest biomass, chipping, supply cost, biomass ...

  2. Midwest Logging Firm Perspectives: Harvesting on Increasingly Parcelized Forestlands

    Directory of Open Access Journals (Sweden)

    Shorna Allred

    2011-01-01

    Full Text Available Loggers play a critical role in the sustainable production of wood and paper products, and harvesting activities contribute to economic health and viability of many Upper Midwest communities in the United States. If the logging sector is unable to procure wood efficiently and economically from an increasingly parcelized land base, the competitive ability of the forest industry could be jeopardized. Little is known about the functions of the logging sector related to the forest resource land base on which they depend, and it is imperative to improve our understanding of this important part of the forest industry. The purpose of this study was to determine prospective attitudes about the future of the logging industry and how trends in forestland parcelization and harvesting mechanization are impacting the logging industry, especially as it relates to smaller tracts of land.

  3. Log-concave Probability Distributions: Theory and Statistical Testing

    DEFF Research Database (Denmark)

    An, Mark Yuing

    1996-01-01

    This paper studies the broad class of log-concave probability distributions that arise in economics of uncertainty and information. For univariate, continuous, and log-concave random variables we prove useful properties without imposing the differentiability of density functions. Discrete...... and multivariate distributions are also discussed. We propose simple non-parametric testing procedures for log-concavity. The test statistics are constructed to test one of the two implicati ons of log-concavity: increasing hazard rates and new-is-better-than-used (NBU) property. The test for increasing hazard...... rates are based on normalized spacing of the sample order statistics. The tests for NBU property fall into the category of Hoeffding's U-statistics...

  4. A Method for Visualizing Transaction Logs of a Faceted OPAC

    Directory of Open Access Journals (Sweden)

    Xi Niu

    2010-12-01

    Full Text Available The authors introduce a method for visualizing user transaction logs from a library catalog application. Simple visualization supporting intuitive or qualitative analysis to quickly make sense of complicated patterns can be a useful supplement or alternative to more common quantitative analysis. To this end, a visual flowchart is created illustrating an individual user session. This visualization can be used to qualitatively grasp user behavior within the application, possibly as an aid to identifying patterns or clusters of use. These flowcharts are created by automatically pre-processing apache transaction logs into an XML representation of meaningful user actions, which are then converted via JavaScript in a web browser to HTML table based flowcharts. The particular toolkit introduced is named Visualization for Understanding Transaction Logs (VUTL, and is available with an open source license. The toolkit has been prototyped with logs from the catalog applications of several academic and one public library.

  5. Ordinal Log-Linear Models for Contingency Tables

    Directory of Open Access Journals (Sweden)

    Brzezińska Justyna

    2016-12-01

    Full Text Available A log-linear analysis is a method providing a comprehensive scheme to describe the association for categorical variables in a contingency table. The log-linear model specifies how the expected counts depend on the levels of the categorical variables for these cells and provide detailed information on the associations. The aim of this paper is to present theoretical, as well as empirical, aspects of ordinal log-linear models used for contingency tables with ordinal variables. We introduce log-linear models for ordinal variables: linear-by-linear association, row effect model, column effect model and RC Goodman’s model. Algorithm, advantages and disadvantages will be discussed in the paper. An empirical analysis will be conducted with the use of R.

  6. Logging, arboricide treatments and regeneration at Budongo Forest

    African Journals Online (AJOL)

    activity was gradually replaced by the taungya system introduced in ... of this study were to: (i) assess the impact of past logging and arboricide .... effects on Budongo forest. ..... Large size individuals such as Croton, Cordia milenii and.

  7. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    Hirasaki, George J.; Mohanty, Kishore K.

    2003-02-10

    The objective of this project was to characterize the fluid properties and fluid-rock interactions which are needed for formation evaluation by NMR well logging. NMR well logging is finding wide use in formation evaluation. The formation parameters commonly estimated were porosity, permeability, and capillary bound water. Special cases include estimation of oil viscosity, residual oil saturation, location of oil/water contact, and interpretation on whether the hydrocarbon is oil or gas.

  8. Some properties of the log-Laplace distribution

    International Nuclear Information System (INIS)

    Uppuluri, V.R.R.

    1980-01-01

    A random variable Y is said to have the Laplace distribution or the double exponential distribution whenever its probability density function is given by lambda exp(-lambda abs. value y), where -infinity 0. The random variable X = exp(Y) is said to have the log-Laplace distribution. With the problem of extrapolation to low doses in dose response curves as motivation, an axiomatic characterization of the log-Laplace distribution is obtained. 1 figure

  9. Development of slimline logging systems for coal and mineral exploration

    International Nuclear Information System (INIS)

    Reeves, D.R.

    1976-01-01

    Recently, interest shown by multinational oil companies in mining prospecting has led to the requirement for more sophisticated slimline logging units, capable of given comparable results to conventional systems. Aspects of operating conditions and logging requirements are discussed, with particular reference to the effect on equipment design. Special consideration is given to the design and calibration of gamma ray, density, neutron, caliper and resistivity tools. Methods of handling data are discussed and the general application of these techniques to mineral work is considered

  10. MCEM algorithm for the log-Gaussian Cox process

    OpenAIRE

    Delmas, Celine; Dubois-Peyrard, Nathalie; Sabbadin, Regis

    2014-01-01

    Log-Gaussian Cox processes are an important class of models for aggregated point patterns. They have been largely used in spatial epidemiology (Diggle et al., 2005), in agronomy (Bourgeois et al., 2012), in forestry (Moller et al.), in ecology (sightings of wild animals) or in environmental sciences (radioactivity counts). A log-Gaussian Cox process is a Poisson process with a stochastic intensity depending on a Gaussian random eld. We consider the case where this Gaussian random eld is ...

  11. Data logging and online reconstruction in H1

    International Nuclear Information System (INIS)

    Fuhrmann, P.; Gerhards, R.; Kruener-Marquis, U.; Olsson, J.E.; Szkutnik, Z.

    1994-01-01

    In spring 1992, the H1 detector at the HERA electron proton collider at DESY came into operation. The high bunch crossing rate and, correspondingly, the large data volumes are placing demanding requirements on the data logging and event reconstruction. Both tasks are performed on an SGI Challenge series computer. This note reviews the development and the experience with the data logging and online reconstruction in H1

  12. Some properties of the log-Laplace distribution

    International Nuclear Information System (INIS)

    Uppuluri, V.R.R.

    1980-08-01

    A random variable γ is said to have the Laplace distribution or the double exponential distribution whenever its probability density function is given by lambda exp(-lambda absolute value (y)), where -infinity 0. The random variable X = exp(γ) is said to have the log-Laplace distribution. With the problem of extrapolation to low doses in dose response curves as a motivation, an axiomatic characterization of the log-Laplace distribution is obtained. 1 figure

  13. Log-periodic self-similarity: an emerging financial law?

    OpenAIRE

    S. Drozdz; F. Grummer; F. Ruf; J. Speth

    2002-01-01

    A hypothesis that the financial log-periodicity, cascading self-similarity through various time scales, carries signatures of a law is pursued. It is shown that the most significant historical financial events can be classified amazingly well using a single and unique value of the preferred scaling factor lambda=2, which indicates that its real value should be close to this number. This applies even to a declining decelerating log-periodic phase. Crucial in this connection is identification o...

  14. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    Hirasaki, George J.; Mohanty, Kishore K.

    2003-02-10

    The objective of this project was to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity.

  15. Make Log Yield Analysis Part of Your Daily Routine

    Science.gov (United States)

    Jan Wiedenbeck; Jeff Palmer; Robert Mayer

    2006-01-01

    You haven't been conducting regular log yield studies because you don't have extra people to assign to the task. Besides, you've been around sawmills your whole life and have an innate sense of how your logs are yielding relative to the price you paid for them. Right? At the USDA Forest Service's hardwood marketing and utilization research lab in...

  16. Lithological control on gas hydrate saturation as revealed by signal classification of NMR logging data

    Science.gov (United States)

    Bauer, Klaus; Kulenkampff, Johannes; Henninges, Jan; Spangenberg, Erik

    2015-09-01

    In this paper, nuclear magnetic resonance (NMR) downhole logging data are analyzed with a new strategy to study gas hydrate-bearing sediments in the Mackenzie Delta (NW Canada). In NMR logging, transverse relaxation time (T2) distribution curves are usually used to determine single-valued parameters such as apparent total porosity or hydrocarbon saturation. Our approach analyzes the entire T2 distribution curves as quasi-continuous signals to characterize the rock formation. We apply self-organizing maps, a neural network clustering technique, to subdivide the data set of NMR curves into classes with a similar and distinctive signal shape. The method includes (1) preparation of data vectors, (2) unsupervised learning, (3) cluster definition, and (4) classification and depth mapping of all NMR signals. Each signal class thus represents a specific pore size distribution which can be interpreted in terms of distinct lithologies and reservoir types. A key step in the interpretation strategy is to reconcile the NMR classes with other log data not considered in the clustering analysis, such as gamma ray, hydrate saturation, and other logs. Our results defined six main lithologies within the target zone. Gas hydrate layers were recognized by their low signal amplitudes for all relaxation times. Most importantly, two subtypes of hydrate-bearing shaly sands were identified. They show distinct NMR signals and differ in hydrate saturation and gamma ray values. An inverse linear relationship between hydrate saturation and clay content was concluded. Finally, we infer that the gas hydrate is not grain coating, but rather, pore filling with matrix support is the preferred growth habit model for the studied formation.

  17. Mitigating Hillslope Erosion After Post-fire Salvage Logging Operations

    Science.gov (United States)

    Robichaud, P. R.; Bone, E. D.; Brown, R. E.

    2017-12-01

    In the past decades, wildfires around the world have continued to increase in size, severity, and cost. Major concerns after wildfires are the increased runoff and erosion due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. Salvage logging is often a post-fire forest management action to recoup the economic loss of the burned timber, yet concerns arise on the impacts of this activity on water quality. Recently, several studies have been conducted to determine the effect of salvage logging on hillslope erosion. Logging skid trails have been cited as being the cause of high erosion during and after salvage operations. We investigated the impacts of adding operational logging slash to skid trails to reduce hillslope erosion after salvage operations on the 2015 North Star Fire, Washington. We implemented well-designed rapid response approach to compare slash treatment effectiveness by monitoring sediment yield and runoff response from hillslopes with a concentrated flow (rill) experiment. Various runoff amounts are incrementally added to 4 m hillslope plots with and without slash treatments. Our initial results suggest that adding logging slash increased ground cover significantly which contributed to an order of magnitude decrease in hillslope erosion. Integrating erosion mitigation strategies into salvage logging operations should be commonplace when hillslope erosion is a concern.

  18. Generating porosity spectrum of carbonate reservoirs using ultrasonic imaging log

    Science.gov (United States)

    Zhang, Jie; Nie, Xin; Xiao, Suyun; Zhang, Chong; Zhang, Chaomo; Zhang, Zhansong

    2018-03-01

    Imaging logging tools can provide us the borehole wall image. The micro-resistivity imaging logging has been used to obtain borehole porosity spectrum. However, the resistivity imaging logging cannot cover the whole borehole wall. In this paper, we propose a method to calculate the porosity spectrum using ultrasonic imaging logging data. Based on the amplitude attenuation equation, we analyze the factors affecting the propagation of wave in drilling fluid and formation and based on the bulk-volume rock model, Wyllie equation and Raymer equation, we establish various conversion models between the reflection coefficient β and porosity ϕ. Then we use the ultrasonic imaging logging and conventional wireline logging data to calculate the near-borehole formation porosity distribution spectrum. The porosity spectrum result obtained from ultrasonic imaging data is compared with the one from the micro-resistivity imaging data, and they turn out to be similar, but with discrepancy, which is caused by the borehole coverage and data input difference. We separate the porosity types by performing threshold value segmentation and generate porosity-depth distribution curves by counting with equal depth spacing on the porosity image. The practice result is good and reveals the efficiency of our method.

  19. A comparison between elemental logs and core data

    International Nuclear Information System (INIS)

    Kerr, S.A.; Grau, J.A.; Schweitzer, J.S.

    1992-01-01

    Neutron-induced gamma-ray spectroscopy, of prompt capture and delayed activation, together with natural gamma-ray measurements, provides a borehole elemental analysis to characterize rock matrix composition. This study involved extensive core and log data in two wells. One well was drilled with a barite-weighted oil-based mud through a shallow marine sand. The other was drilled with fresh water-based mud through a channel sand, mudstone sequence overlying limestone. The results illustrate the importance of a suitable core sampling strategy and the problems associated with matching core to log data. Possible inaccuracies from the modelling of Ca-, Fe- and S-bearing minerals have been determined. A method for correcting the total measured aluminium concentration for that due to the borehole mud has been successfully tested against aluminium concentrations measured in the cleaned core samples. Estimates of the overall accuracy and precision of the elemental logging concentrations are obtained by comparing the log results with those obtained from the laboratory core analysis. A comprehensive core elemental analysis can also provide useful insight into the way other logs, such as the photoelectric factor or formation thermal neutron macroscopic absorption cross section, are influenced by minor and trace elements. Differences between calculated values from elemental logs and measured macroscopic parameters provide additional data for a more detailed understanding of the rock properties. (Author)

  20. Latent log-linear models for handwritten digit classification.

    Science.gov (United States)

    Deselaers, Thomas; Gass, Tobias; Heigold, Georg; Ney, Hermann

    2012-06-01

    We present latent log-linear models, an extension of log-linear models incorporating latent variables, and we propose two applications thereof: log-linear mixture models and image deformation-aware log-linear models. The resulting models are fully discriminative, can be trained efficiently, and the model complexity can be controlled. Log-linear mixture models offer additional flexibility within the log-linear modeling framework. Unlike previous approaches, the image deformation-aware model directly considers image deformations and allows for a discriminative training of the deformation parameters. Both are trained using alternating optimization. For certain variants, convergence to a stationary point is guaranteed and, in practice, even variants without this guarantee converge and find models that perform well. We tune the methods on the USPS data set and evaluate on the MNIST data set, demonstrating the generalization capabilities of our proposed models. Our models, although using significantly fewer parameters, are able to obtain competitive results with models proposed in the literature.

  1. The human factors of implementing shift work in logging operations.

    Science.gov (United States)

    Mitchell, D L; Gallagher, T V; Thomas, R E

    2008-10-01

    A fairly recent development in the forest industry is the use of shift work in logging in the southeastern U.S. Logging company owners are implementing shift work as an opportunity to increase production and potentially reduce the cost of producing each unit of wood, without consideration of the potential impacts on the logging crew. There are many documented physiological and psychological impacts on workers from shift work in a variety of industries, although few address forestry workers in the U.S. Semi-structured interviews were performed to gather information about how logging company owners were implementing shift work in seven southeastern states. Data collected during the interviews included employee turnover, shift hours, shift scheduling, safety considerations, and production impacts. Various work schedules were employed. The majority of the schedules encompassed less than 24 hours per day. Permanent and rotating shift schedules were found. None of the logging company owners used more than two crews in a 24-hour period. Additional safety precautions were implemented as a result of working after dark. No in-woods worker accidents or injuries were reported by any of those interviewed. Results indicate that a variety of work schedules can be successfully implemented in the southeastern logging industry.

  2. PUMA Internet Task Logging Using the IDAC-1

    Directory of Open Access Journals (Sweden)

    K. N. Tarchanidis

    2014-08-01

    Full Text Available This project uses an IDAC-1 board to sample the joint angle position of the PUMA 76 1 robot and log the results on a computer. The robot is at the task location and the logging computer is located in a different one. The task the robot is performing is based on a Pseudo Stereo Vision System (PSVS. Internet is the transport media. The protocol used in this project is UDP/IP. The actual angle is taken straight from the PUMA controller. High-resolution potentiometers are connected on each robot joint and are buffered and sampled as potential difference on an A/D converter integrated on the IDAC-1. The logging computer through the Internet acting as client asks for the angle set, the IDAC-1 responds as server with the 10-bit resolution sampling of the joint position. The whole task is logged in a file on the logging computer. This application can give the ability to the Internet user to monitor and log the robot tasks anywhere in the Word Wide Web (www.

  3. The frequency and level of sweep in mixed hardwood saw logs in the eastern United States

    Science.gov (United States)

    Peter Hamner; Marshall S. White; Philip A. Araman

    2007-01-01

    Hardwood sawmills traditionally saw logs in a manner that either orients sawlines parallel to the log central axis (straight sawing) or the log surface (allowing for taper). Sweep is characterized as uniform curvature along the entire length of a log. For logs with sweep, lumber yield losses from straight and taper sawing increase with increasing levels of sweep. Curve...

  4. Modeling and validating the grabbing forces of hydraulic log grapples used in forest operations

    Science.gov (United States)

    Jingxin Wang; Chris B. LeDoux; Lihai Wang

    2003-01-01

    The grabbing forces of log grapples were modeled and analyzed mathematically under operating conditions when grabbing logs from compact log piles and from bunch-like log piles. The grabbing forces are closely related to the structural parameters of the grapple, the weight of the grapple, and the weight of the log grabbed. An operational model grapple was designed and...

  5. 40 CFR 146.66 - Logging, sampling, and testing prior to new well operation.

    Science.gov (United States)

    2010-07-01

    ... cement bond and variable density log, and a temperature log after the casing is set and cemented. (ii..., gamma ray, and fracture finder logs before the casing is installed; and (B) A cement bond and variable density log, and a temperature log after the casing is set and cemented. (iii) The Director may allow the...

  6. Regeneration and management of lesser known timber species in the Peruvian Amazon following disturbance by logging

    DEFF Research Database (Denmark)

    Karsten, Rune Juelsborg; Meilby, Henrik; Larsen, Jørgen Bo

    2014-01-01

    Following the principles of Reduced Impact Logging (RIL) the construction of roads and log landings together with logging gaps are the most profound direct impacts that a forest operation has on the forest. While the effects of logging gaps have been studied in detail, the impacts of road and log...

  7. The application of borehole logging to characterize the hydrogeology of the Faultless site, Central Nevada Test Area

    International Nuclear Information System (INIS)

    Chapman, J.B.; Mihevc, T.M.; Lyles, B.F.

    1994-08-01

    The Central Nevada Test Area was the site of the Faultless underground nuclear test that could be a source of radionuclide contamination to aquifers in Hot Creek Valley, Nevada. Field studies in 1992 and 1993 have used hydrologic logging and water sampling to determine the adequacy of the current groundwater monitoring network and the status of water-level recovery to pre-shot levels in the nuclear chimney. The field studies have determined that there is a possibility for contaminant migration away from the Faultless event though the pre-event water level has not been attained, while new data raise questions about the ability of the current monitoring network to detect migration. Hydrologic logs from the postshot hole (drilled into the chimney created by the nuclear detonation) reveal inflow around 485 m below land surface. The physical and chemical characteristics of the inflow water indicate that its source is much deeper in the chimney, perhaps driven upward in a convection cell generated by heat near the nuclear cavity. Logging and sampling at monitoring wells HTH-1 and HTH-2 revealed that the completion of HTH-1 may be responsible for its elevated water level (as compared to pre-nuclear test levels) and may have also created a local mound in the water table in the alluvium that accounts for higher post-test water levels at HTH-2. This mound would serve to divert flow around the monitoring wells, so that only migration of contaminants through the underlying, higher pressure, volcanic units is currently monitored. A hydraulic high found in an abandoned hole located between the nuclear chimney and the monitoring wells further reduces the likelihood of HTH-1 or HTH-2 intercepting contaminant migration

  8. Closed expressions for $\\int_{0}^{1} t^{-1} log^{n-1}t log^{p}(1 - t) dt$

    CERN Document Server

    Kölbig, Kurt Siegfried

    1982-01-01

    Closed expressions for the integral integral /sub 0//sup 1/ t/sup -1/ log/sup n-1/t log/sup p/(1-t)dt, whose general form is given elsewhere, are listed for n=1(1)9, p=1(1)9. A formula is derived which allows an easy evaluation of these expressions by formula manipulation on a computer. The majority of the above expressions are given in a microfiche supplement to the paper.

  9. Nuclear instrumentation for research reactors

    International Nuclear Information System (INIS)

    Hofer, Carlos G.; Pita, Antonio; Verrastro, Claudio A.; Maino, Eduardo J.

    1997-01-01

    The nuclear instrumentation for research reactors in Argentina was developed in 70'. A gradual modernization of all the nuclear instrumentation is planned. It includes start-up and power range instrumentation, as well as field monitors, clamp, scram and rod movement control logic. The new instrumentation is linked to a computer network, based on real time operating system for data acquisition, display and logging. This paper describes the modules and whole system aspects. (author). 2 refs

  10. Nuclear law - Nuclear safety

    International Nuclear Information System (INIS)

    Pontier, Jean-Marie; Roux, Emmanuel; Leger, Marc; Deguergue, Maryse; Vallar, Christian; Pissaloux, Jean-Luc; Bernie-Boissard, Catherine; Thireau, Veronique; Takahashi, Nobuyuki; Spencer, Mary; Zhang, Li; Park, Kyun Sung; Artus, J.C.

    2012-01-01

    This book contains the contributions presented during a one-day seminar. The authors propose a framework for a legal approach to nuclear safety, a discussion of the 2009/71/EURATOM directive which establishes a European framework for nuclear safety in nuclear installations, a comment on nuclear safety and environmental governance, a discussion of the relationship between citizenship and nuclear, some thoughts about the Nuclear Safety Authority, an overview of the situation regarding the safety in nuclear waste burying, a comment on the Nome law with respect to electricity price and nuclear safety, a comment on the legal consequences of the Fukushima accident on nuclear safety in the Japanese law, a presentation of the USA nuclear regulation, an overview of nuclear safety in China, and a discussion of nuclear safety in the medical sector

  11. Local regularity analysis of strata heterogeneities from sonic logs

    Directory of Open Access Journals (Sweden)

    S. Gaci

    2010-09-01

    Full Text Available Borehole logs provide geological information about the rocks crossed by the wells. Several properties of rocks can be interpreted in terms of lithology, type and quantity of the fluid filling the pores and fractures.

    Here, the logs are assumed to be nonhomogeneous Brownian motions (nhBms which are generalized fractional Brownian motions (fBms indexed by depth-dependent Hurst parameters H(z. Three techniques, the local wavelet approach (LWA, the average-local wavelet approach (ALWA, and Peltier Algorithm (PA, are suggested to estimate the Hurst functions (or the regularity profiles from the logs.

    First, two synthetic sonic logs with different parameters, shaped by the successive random additions (SRA algorithm, are used to demonstrate the potential of the proposed methods. The obtained Hurst functions are close to the theoretical Hurst functions. Besides, the transitions between the modeled layers are marked by Hurst values discontinuities. It is also shown that PA leads to the best Hurst value estimations.

    Second, we investigate the multifractional property of sonic logs data recorded at two scientific deep boreholes: the pilot hole VB and the ultra deep main hole HB, drilled for the German Continental Deep Drilling Program (KTB. All the regularity profiles independently obtained for the logs provide a clear correlation with lithology, and from each regularity profile, we derive a similar segmentation in terms of lithological units. The lithological discontinuities (strata' bounds and faults contacts are located at the local extrema of the Hurst functions. Moreover, the regularity profiles are compared with the KTB estimated porosity logs, showing a significant relation between the local extrema of the Hurst functions and the fluid-filled fractures. The Hurst function may then constitute a tool to characterize underground heterogeneities.

  12. Lithostratigraphy from downhole logs in Hole AND-1B, Antarctica

    Science.gov (United States)

    Williams, Trevor; Morin, Roger H.; Jarrard, Richard D.; Jackolski, Chris L.; Henrys, Stuart A.; Niessen, Frank; Magens, Diana; Kuhn, Gerhard; Monien, Donata; Powell, Ross D.

    2012-01-01

    The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sediment in Hole AND–1B, representing the past 12 m.y. of glacial history. Downhole geophysical logs were acquired to a depth of 1018 mbsf (meters below seafloor), and are complementary to data acquired from the core. The natural gamma radiation (NGR) and magnetic susceptibility logs are particularly useful for understanding lithological and paleoenvironmental change at ANDRILL McMurdo Ice Shelf Hole AND–1B. NGR logs cover the entire interval from the seafloor to 1018 mbsf, and magnetic susceptibility and other logs covered the open hole intervals between 692 and 1018 and 237–342 mbsf. In the upper part of AND–1B, clear alternations between low and high NGR values distinguish between diatomite (lacking minerals containing naturally radioactive K, U, and Th) and diamictite (containing K-bearing clays, K-feldspar, mica, and heavy minerals). In the lower open hole logged section, NGR and magnetic susceptibility can also distinguish claystones (rich in K-bearing clay minerals, relatively low in magnetite) and diamictites (relatively high in magnetite). Sandstones can be distinguished by their high resistivity values in AND–1B. On the basis of these three downhole logs, diamictite, claystones, and sandstones can be predicted correctly for 74% of the 692–1018 mbsf interval. The logs were then used to predict facies for the 6% of this interval that was unrecovered by coring. Given the understanding of the physical property characteristics of different facies, it is also possible to identify subtle changes in lithology from the physical properties and help refine parts of the lithostratigraphy, for example, the varying terrigenous content of diatomites and the transitions from subice diamictite to open-water diatomite.

  13. The application of radiation logs to groundwater hydrology

    Energy Technology Data Exchange (ETDEWEB)

    Scott Keys, W [United States Geological Survey, Denver, CO (United States)

    1967-05-15

    The drilling of exploratory holes to determine the availability of groundwater and to plan the most economical methods of water development is expensive. The only technique available at present for obtaining geological and hydrological information through the casing of pre-existing water wells and other boreholes is by radiation logging. Up to now these logging techniques have been little used in groundwater hydrology. This report describes inexpensive portable radiation logging equipment that is available or has been developed for groundwater studies in connection with a general research project on the application of borehole geophysics in groundwater hydrology. It is possible to obtain data on the following: the source, velocity, and chemical quality of groundwater; the location, extent, geometry, bulk density, porosity, permeability, and specific yield of aquifers and associated strata; and the position of casings, casing collars, leaks, perforations, and cement. The radiation logs employed include natural gamma, gamma-gamma, neutron-gamma. neutron epithermal-neutron. and radioactive tracer. The following radioisotopes are utilized: cobalt-60, plutonium-239, americium-241, and iodine-131. Typical radiation logs obtained by the various techniques are described and examples are given of practical applications of radiation logging to groundwater investigations. The applications cited are studies of perched water in basaltic rocks and associated sedimentary strata; the porosity, moisture content, and position of zones into which water was injected in volcanic tuff; the position of the interface between brine and fresh water in fine-grained carbonate rocks and associated fine clastic rocks; the interpretation of porosity from a neutron log; and the location by means of a radioactive tracer of the more permeable fracture zones in a well penetrating crystalline rock. (author)

  14. Characterization of reservoir fractures using conventional geophysical logging

    Directory of Open Access Journals (Sweden)

    Paitoon Laongsakul

    2011-04-01

    Full Text Available In hydrocarbon exploration fractures play an important role as possible pathways for the hydrocarbon flow and bythis enhancing the overall formation’s permeability. Advanced logging methods for fracture analysis, like the boreholeacoustic televiewer and Formation Microscanner (FMS are available, but these are additional and expensive tools. However,open and with water or hydrocarbon filled fractures are also sensitive to electrical and other conventional logging methods.For this study conventional logging data (electric, seismic, etc were available plus additional fracture information from FMS.Taking into account the borehole environment the results show that the micro-spherically focused log indicates fractures byshowing low resistivity spikes opposite open fractures, and high resistivity spikes opposite sealed ones. Compressional andshear wave velocities are reduced when passing trough the fracture zone, which are assumed to be more or less perpendicularto borehole axis. The photoelectric absorption curve exhibit a very sharp peak in front of a fracture filled with bariteloaded mud cake. The density log shows low density spikes that are not seen by the neutron log, usually where fractures,large vugs, or caverns exist. Borehole breakouts can cause a similar effect on the logging response than fractures, but fracturesare often present when this occurs. The fracture index calculation by using threshold and input weight was calculatedand there was in general a good agreement with the fracture data from FMS especially in fracture zones, which mainlycontribute to the hydraulic system of the reservoir. Finally, the overall results from this study using one well are promising,however further research in the combination of different tools for fracture identification is recommended as well as the useof core for further validation.

  15. Industrial applications of nuclear technology

    International Nuclear Information System (INIS)

    Vargas, Celso

    2010-01-01

    Industrial applications of nuclear technology have been very diverse worldwide. This type of technology has begun to introduce in Costa Rica to evaluate and improve different industrial processes. These applications have been classified into two or three categories, according to the criteria used. Nucleonic control systems, the gamma logging and radiotracers are determined. (author) [es

  16. Nuclear instrumentation for research reactors; Instrumentacion nuclear para reactores nucleares de investigacion

    Energy Technology Data Exchange (ETDEWEB)

    Hofer, Carlos G.; Pita, Antonio; Verrastro, Claudio A.; Maino, Eduardo J. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Unidad de Actividades de Reactores y Centrales Nucleares. Sector Instrumentacion y Control

    1997-10-01

    The nuclear instrumentation for research reactors in Argentina was developed in 70`. A gradual modernization of all the nuclear instrumentation is planned. It includes start-up and power range instrumentation, as well as field monitors, clamp, scram and rod movement control logic. The new instrumentation is linked to a computer network, based on real time operating system for data acquisition, display and logging. This paper describes the modules and whole system aspects. (author). 2 refs.

  17. Mineral nuclear exploration

    International Nuclear Information System (INIS)

    Filippov, E.M.

    1978-01-01

    The information on quantitative determination in rocks of water (humidity), rock-forming chemical elements, and various usefull components are presented. When considering separate chemical elements given are brief information on their content in natural objects, nuclear properties (the main reactions, their cross sections, isotope characteristics etc.). Possibilities of different nuclear methods in determination of chemical element concentrations in ores and rocks are analyzed. The greatest attention is paid to analysis of methods, based on gamma quantum and neutron irradiation. The results of application of laboratory nuclear-physical methods of rapid analysis are briefly considered, whereas the results of different field methods of nuclear exploration are considered in detail: field survey, well logging, inspection of mine roadway walls. In the appendix general information on chemical elements and sensitivity thresholds of certain activation methods are presented

  18. Logs of Paleoseismic Excavations Across the Central Range Fault, Trinidad

    Science.gov (United States)

    Crosby, Christopher J.; Prentice, Carol S.; Weber, John; Ragona, Daniel

    2009-01-01

    This publication makes available maps and trench logs associated with studies of the Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. Our studies were conducted in 2001 and 2002. We mapped geomorphic features indicative of active faulting along the right-lateral, Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. We excavated trenches at two sites, the Samlalsingh and Tabaquite sites. At the Samlalsingh site, sediments deposited after the most recent fault movement bury the fault, and the exact location of the fault was unknown until we exposed it in our excavations. At this site, we excavated a total of eleven trenches, six of which exposed the fault. The trenches exposed fluvial sediments deposited over a strath terrace developed on Miocene bedrock units. We cleaned the walls of the excavations, gridded the walls with either 1 m X 1 m or 1 m X 0.5 m nail and string grid, and logged the walls in detail at a scale of 1:20. Additionally, we described the different sedimentary units in the field, incorporating these descriptions into our trench logs. We mapped the locations of the trenches using a tape and compass. Our field logs were scanned, and unit contacts were traced in Adobe Illustrator. The final drafted logs of all the trenches are presented here, along with photographs showing important relations among faults and Holocene sedimentary deposits. Logs of south walls were reversed in Illustrator, so that all logs are drafted with the view direction to the north. We collected samples of various materials exposed in the trench walls, including charcoal samples for radiocarbon dating from both faulted and unfaulted deposits. The locations of all samples collected are shown on the logs. The ages of seventeen of the charcoal samples submitted for radiocarbon analysis at the University of Arizona Accelerator Mass Spectrometry Laboratory in Tucson, Ariz., are given in Table 1. Samples found in

  19. Biological legacies buffer local species extinction after logging.

    Science.gov (United States)

    Rudolphi, Jörgen; Jönsson, Mari T; Gustafsson, Lena; Bugmann, H

    2014-02-01

    Clearcutting has been identified as a main threat to forest biodiversity. In the last few decades, alternatives to clearcutting have gained much interest. Living and dead trees are often retained after harvest to serve as structural legacies to mitigate negative effects of forestry. However, this practice is widely employed without information from systematic before-after control-impact studies to assess the processes involved in species responses after clearcutting with retention. We performed a large-scale survey of the occurrence of logging-sensitive and red-listed bryophytes and lichens before and after clearcutting with the retention approach. A methodology was adopted that, for the first time in studies on retention approaches, enabled monitoring of location-specific substrates. We used uncut stands as controls to assess the variables affecting the survival of species after a major disturbance. In total, 12 bryophyte species and 27 lichen species were analysed. All were classified as sensitive to logging, and most species are also currently red-listed. We found that living and dead trees retained after final harvest acted as refugia in which logging-sensitive species were able to survive for 3 to 7 years after logging. Depending on type of retention and organism group, between 35% and 92% of the species occurrences persisted on retained structures. Most species observed outside retention trees or patches disappeared. Larger pre-harvest population sizes of bryophytes on dead wood increased the survival probability of the species and hence buffered the negative effects of logging. Synthesis and applications . Careful spatial planning of retention structures is required to fully embrace the habitats of logging-sensitive species. Bryophytes and lichens persisted to a higher degree in retention patches compared to solitary trees or in the clearcut area. Retaining groups of trees in logged areas will help to sustain populations of species over the clearcut phase

  20. Athabasca tar sand reservoir properties derived from cores and logs

    International Nuclear Information System (INIS)

    Woodhouse, R.

    1976-01-01

    Log interpretation parameters for the Athabasca Tar Sand Lease No. 24 have been determined by careful correlation with Dean and Stark core analysis data. Significant expansion of Athabasca cores occurs as overburden pressure is removed. In the more shaly sands the core analysis procedures remove adsorbed water from the clays leading to further overestimation of porosity and free water volume. Log interpretation parameters (R/sub w/ = 0.5 ohm . m and m = n = 1.5) were defined by correlation with the weight of tar as a fraction of the weight of rock solids (grain or dry weight fraction of tar). This quantity is independent of the water content of the cores, whereas porosity and the weight of tar as a fraction of the bulk weight of fluids plus solids (bulk weight fraction) are both dependent on water content. Charts are provided for the conversion of bulk weight fraction of fluids to porosity; grain weight fraction of fluids to porosity; log derived porosity and core grain weight tar to water saturation. Example results show that the core analysis grain weight fraction of tar is adequately matched by the log analyses. The log results provide a better representation of the reservoir fluid volumes than the core analysis data

  1. Research on Test-bench for Sonic Logging Tool

    Directory of Open Access Journals (Sweden)

    Xianping Liu

    2016-01-01

    Full Text Available In this paper, the test-bench for sonic logging tool is proposed and designed to realize automatic calibration and testing of the sonic logging tool. The test-bench System consists of Host Computer, Embedded Controlling Board, and functional boards. The Host Computer serves as the Human Machine Interface (HMI and processes uploaded data. The software running on Host Computer is designed on VC++, which is developed based on multithreading, Dynamic Linkable Library (DLL and Multiple Document Interface (MDI techniques. The Embedded Controlling Board uses ARM7 as the microcontroller and communicates with Host Computer via Ethernet. The Embedded Controlling Board software is realized based on embedded uclinux operating system with a layered architecture. The functional boards are designed based on Field Programmable Gate Array (FPGA and provide test interfaces for the logging tool. The functional board software is divided into independent sub-modules that can repeatedly be used by various functional boards and then integrated those sub-modules in the top layer. With the layered architecture and modularized design, the software system is highly reliable and extensible. With the help of designed system, a test has been conducted quickly and successfully on the electronic receiving cabin of the sonic logging tool. It demonstrated that the system could greatly improve the production efficiency of the sonic logging tool.

  2. Radiation protection in well logging: case studies in the Sudan

    International Nuclear Information System (INIS)

    Eltayeb, B. A.

    2010-12-01

    This study is performed to improve radiation protection level in well logging include tow case studies in Sudan (Lost or misplaced sources). General review of radiation and radiation protection basic concept is highlighted discussed. Also preview of well logging practice and source of radiation use in well logging, safety of radiation sources, storage and manage of not use sources (weak sources) and protection of worker and potential exposure for public and worker, investigations in cause of lost or misplaced sources in well. Assessment was made in well logging using checklist prepared in accordance with the International Atomic Energy Agency IAEA basic safety standard, International Committee for Radiological Protection ICRP and safety in transport of radiation sources. The checklist includes all requirement of radiation protection. It is found that all requirement was present except the delay of calibration of radiation detectors, the movement of radiation sources form storage to base of manipulated area need adequate care for shielding and safe transport and personal monitoring service must be provide in Sudan. Investigation was made in cause of lose of nine radiation source in well it is found that all those sources were loss in different depth in the well and with deferent location and there was no risk because there was no contamination of fluids which caused by damage of loss sources. Some recommendations were stated that, if implemented could improve the status of radiation protection in well logging. (Author)

  3. [Using log-binomial model for estimating the prevalence ratio].

    Science.gov (United States)

    Ye, Rong; Gao, Yan-hui; Yang, Yi; Chen, Yue

    2010-05-01

    To estimate the prevalence ratios, using a log-binomial model with or without continuous covariates. Prevalence ratios for individuals' attitude towards smoking-ban legislation associated with smoking status, estimated by using a log-binomial model were compared with odds ratios estimated by logistic regression model. In the log-binomial modeling, maximum likelihood method was used when there were no continuous covariates and COPY approach was used if the model did not converge, for example due to the existence of continuous covariates. We examined the association between individuals' attitude towards smoking-ban legislation and smoking status in men and women. Prevalence ratio and odds ratio estimation provided similar results for the association in women since smoking was not common. In men however, the odds ratio estimates were markedly larger than the prevalence ratios due to a higher prevalence of outcome. The log-binomial model did not converge when age was included as a continuous covariate and COPY method was used to deal with the situation. All analysis was performed by SAS. Prevalence ratio seemed to better measure the association than odds ratio when prevalence is high. SAS programs were provided to calculate the prevalence ratios with or without continuous covariates in the log-binomial regression analysis.

  4. Automatic Data Logging and Quality Analysis System for Mobile Devices

    Directory of Open Access Journals (Sweden)

    Yong-Yi Fanjiang

    2017-01-01

    Full Text Available The testing phase of mobile device products includes two important test projects that must be completed before shipment: the field trial and the beta user trial. During the field trial, the product is certified based on its integration and stability with the local operator’s system, and, during the beta user trial, the product is certified by multiple users regarding its daily use, where the goal is to detect and solve early problems. In the traditional approach used to issue returns, testers must log into a web site, fill out a problem form, and then go through a browser or FTP to upload logs; however, this is inconvenient, and problems are reported slowly. Therefore, we propose an “automatic logging analysis system” (ALAS to construct a convenient test environment and, using a record analysis (log parser program, automate the parsing of log files and have questions automatically sent to the database by the system. Finally, the mean time between failures (MTBF is used to establish measurement indicators for the beta user trial.

  5. Pinpointing water entries using pulsed neutron and Production logging tools

    International Nuclear Information System (INIS)

    Mukerji, P.; Oluwa, J.

    2003-01-01

    A successful work over requires a comprehensive understanding of fluid entries into the wellbore and fluid contact movement in the reservoir. Such information can be obtained by a combination of production logs and saturation-monitoring measurements. The ability to combine pulsed neutron and production logging tools provides the operator with better diagnostics for identifying candidates for remedial actions and greatly increases the possibility of a successful well intervention. Advances in pulsed neutron spectroscopy tools have improved the accuracy and precision of measured carbon/oxygen ratios. Some of the improvements in accuracy and precision have resulted from better tool characterization in a wider variety of logging environments in the calibration facility and new spectral standards. Coincident with the advances in pulsed neutron spectroscopy has been the development of production logging measurements run on a platform common. We will show how the application of pulsed neutron and production logs can optimize subsequent well intervention to reduce water production and/or increase oil production

  6. Preliminary report on NTS spectral gamma logging and calibration models

    International Nuclear Information System (INIS)

    Mathews, M.A.; Warren, R.G.; Garcia, S.R.; Lavelle, M.J.

    1985-01-01

    Facilities are now available at the Nevada Test Site (NTS) in Building 2201 to calibrate spectral gamma logging equipment in environments of low radioactivity. Such environments are routinely encountered during logging of holes at the NTS. Four calibration models were delivered to Building 2201 in January 1985. Each model, or test pit, consists of a stone block with a 12-inch diameter cored borehole. Preliminary radioelement values from the core for the test pits range from 0.58 to 3.83% potassium (K), 0.48 to 29.11 ppm thorium (Th), and 0.62 to 40.42 ppm uranium (U). Two satellite holes, U19ab number2 and U19ab number3, were logged during the winter of 1984-1985. The response of these logs correlates with contents of the naturally radioactive elements K. Th. and U determined in samples from petrologic zones that occur within these holes. Based on these comparisons, the spectral gamma log aids in the recognition and mapping of subsurface stratigraphic units and alteration features associated with unusual concentration of these radioactive elements, such as clay-rich zones

  7. Formation factor logging in-situ by electrical methods. Background and methodology

    International Nuclear Information System (INIS)

    Loefgren, Martin; Neretnieks, Ivars

    2002-10-01

    Matrix diffusion has been identified as one of the most important mechanisms governing the retardation of radionuclides escaping from a deep geological repository for nuclear waste. Radionuclides dissolved in groundwater flowing in water-bearing fractures will diffuse into water filled micropores in the rock. Important parameters governing the matrix diffusion are the formation factor, the surface diffusion and sorption. This report focuses on the formation factor in undisturbed intrusive igneous rock and the possibility of measuring this parameter in-situ. The background to and the methodology of formation factor logging in-situ by electrical methods are given. The formation factor is here defined as a parameter only depending on the geometry of the porous system and not on the diffusing specie. Traditionally the formation factor has been measured by through diffusion experiments on core samples, which are costly and time consuming. It has been shown that the formation factor could also be measured by electrical methods that are faster and less expensive. Previously this has only been done quantitatively in the laboratory on a centimetre or decimetre scale. When measuring the formation factor in-situ in regions with saline groundwater only the rock resistivity and the pore water resistivity are needed. The rock resistivity could be obtained by a variety of geophysical downhole tools. Water-bearing fractures disturb the measurements and data possibly affected by free water has to be sorted out. This could be done without loosing too much data if the vertical resolution of the tool is high enough. It was found that the rock resistivity tool presently used by SKB are neither quantitative or have enough vertical resolution. Therefore the slimhole Dual-Laterolog from Antares was tested with good results. This tool has a high vertical resolution and gives quantitative rock resistivities that need no correction. At present there is no method of directly obtaining the

  8. Formation factor logging in-situ by electrical methods. Background and methodology

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Martin; Neretnieks, Ivars [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2002-10-01

    Matrix diffusion has been identified as one of the most important mechanisms governing the retardation of radionuclides escaping from a deep geological repository for nuclear waste. Radionuclides dissolved in groundwater flowing in water-bearing fractures will diffuse into water filled micropores in the rock. Important parameters governing the matrix diffusion are the formation factor, the surface diffusion and sorption. This report focuses on the formation factor in undisturbed intrusive igneous rock and the possibility of measuring this parameter in-situ. The background to and the methodology of formation factor logging in-situ by electrical methods are given. The formation factor is here defined as a parameter only depending on the geometry of the porous system and not on the diffusing specie. Traditionally the formation factor has been measured by through diffusion experiments on core samples, which are costly and time consuming. It has been shown that the formation factor could also be measured by electrical methods that are faster and less expensive. Previously this has only been done quantitatively in the laboratory on a centimetre or decimetre scale. When measuring the formation factor in-situ in regions with saline groundwater only the rock resistivity and the pore water resistivity are needed. The rock resistivity could be obtained by a variety of geophysical downhole tools. Water-bearing fractures disturb the measurements and data possibly affected by free water has to be sorted out. This could be done without loosing too much data if the vertical resolution of the tool is high enough. It was found that the rock resistivity tool presently used by SKB are neither quantitative or have enough vertical resolution. Therefore the slimhole Dual-Laterolog from Antares was tested with good results. This tool has a high vertical resolution and gives quantitative rock resistivities that need no correction. At present there is no method of directly obtaining the

  9. Simultaneous thermal neutron decay time and porosity logging system

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

    1979-01-01

    A simultaneous pulsed neutron porosity and thermal neutron capture cross section logging system is provided for radiological well logging of subsurface earth formations. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector, and a combination gamma ray and fast neutron detector is moved through a borehole. Repetitive bursts of neutrons irradiate the earth formations; and, during the bursts, the fast neutron and epithermal neutron populations are sampled. During the interval between bursts the thermal neutron capture gamma ray population is sampled in two or more time intervals. The fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity phi. The capture gamma ray measurements are combined to provide a simultaneous determination of the thermal neutron capture cross section Σ

  10. Unified electronic unit for miniature radioactivity logging equipment

    International Nuclear Information System (INIS)

    Bragin, A.A.; Goldshtejn, L.M.; Fedorov, R.F.; Shikhman, A.S.

    1981-01-01

    Appropriateness and urgency of the unification of components of radioactivity logging equipment used for the investigation of wells at solid mineral deposits is substantiated. A two-channel electronic unit for miniature equipment for radioactivity logging is described and its basic specifications and performance are given. All functional assemblies of the unit are structurally made in the form of printed circuit boards placed in a pan-shaped chassis 28 mm in diameter. The unit's general design provides for the possibility to attach two probes with detection devices to the unit. The unit is used in the two-channel radioactivity logging instrument ''Kura-2'' and in the two-channel radiometer ''RUR-2''. The outer diameter of these instruments is 48 mm and they ensure the investigation of ore and coal wells with a combination radioactivity methods [ru

  11. TENSOR DECOMPOSITIONS AND SPARSE LOG-LINEAR MODELS

    Science.gov (United States)

    Johndrow, James E.; Bhattacharya, Anirban; Dunson, David B.

    2017-01-01

    Contingency table analysis routinely relies on log-linear models, with latent structure analysis providing a common alternative. Latent structure models lead to a reduced rank tensor factorization of the probability mass function for multivariate categorical data, while log-linear models achieve dimensionality reduction through sparsity. Little is known about the relationship between these notions of dimensionality reduction in the two paradigms. We derive several results relating the support of a log-linear model to nonnegative ranks of the associated probability tensor. Motivated by these findings, we propose a new collapsed Tucker class of tensor decompositions, which bridge existing PARAFAC and Tucker decompositions, providing a more flexible framework for parsimoniously characterizing multivariate categorical data. Taking a Bayesian approach to inference, we illustrate empirical advantages of the new decompositions. PMID:29332971

  12. The Message Logging System for NOνA Experiment

    International Nuclear Information System (INIS)

    Lu Qiming; Kowalkowski, J B; Biery, K A

    2011-01-01

    The message logging system provides the infrastructure for all of the distributed processes in the data acquisition (DAQ) to report status messages of various severities in a consistent manner to a central location, as well as providing the tools for displaying and archiving the messages. The message logging system has been developed over a decade, and has been run successfully on CDF and CMS experiments. The most recent work to the message logging system is to build it as a stand-alone package with the name MessageFacility which works for any generic framework or applications, with NOνA as the first driving user. System designs and architectures, as well as the efforts of making it a generic library will be discussed. We also present new features that have been added.

  13. Mining Experiential Patterns from Game-Logs of Board Game

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2015-01-01

    Full Text Available In board games, game-logs record past game processes, which can be regarded as an accumulation of experience. Similar to a real person, a computer player can gradually increase its skill by learning from game-logs. Therefore, the game becomes more interesting. This paper proposes an extensible approach to mine experiential patterns from increasing game-logs. The computer player improves its strategies by utilizing these growing patterns, just as it acquires experience. To evaluate the effect and performance of the approach, we designed a sample board game as a test platform and elaborated an experiment consisting of a series of tests. Experimental results show that our approach is effective and efficient.

  14. DNA quantification of basidiomycetous fungi during storage of logging residues

    Directory of Open Access Journals (Sweden)

    Isabella Børja

    2015-04-01

    Full Text Available The demand for bioenergy caused an increased use of logging residues, branches and treetops that were previously left on the ground after harvesting. Residues are stored outdoors in piles and it is unclear to what extent fungi transform this material. Our objective was to quantify the amount of wood degrading fungi during storage using quantitative real-time PCR (qPCR to detect basidiomycetous DNA in logging residues, a novel approach in this field. We found that the qPCR method was accurate in quantifying the fungal DNA during storage. As the moisture content of the piled logging residues decreased during the storage period, the fungal DNA content also decreased. Scots pine residues contained more fungal DNA than residues from Norway spruce. Loose piles had generally more fungal DNA than bundled ones.

  15. Cause of depth error of borehole logging and its correction

    International Nuclear Information System (INIS)

    Iida, Yoshimasa; Ikeda, Koki; Tsuruta, Tadahiko; Ito, Hiroaki; Goto, Junichi.

    1996-01-01

    Data by borehole logging can be used for detailed analysis of geological structures. Depths measured by portable borehole loggers commonly shift a few meters on the level of 400 to 500 meters deep. Therefore, the cause of depth error has to be recognized to make proper corrections for detailed structural analysis. Correlation between depths of drill core and in-rod radiometric logging has been performed in detail on exploration drill holes in the Athabasca basin, Canada. As a result, a common tendency of logging depth shift has been recognized, and an empirical formula (quadratic equation) for this has been obtained. The physical meaning of the formula and the cause of the depth error has been considered. (author)

  16. Site characterization and validation - geophysical single hole logging

    International Nuclear Information System (INIS)

    Andersson, Per

    1989-05-01

    A total of 15 boreholes have been drilled for preliminary characterization of a previously unexplored site at the 360 and 385 m level in the Stripa mine. To adequately described the rock mass in the vicinity of these boreholes, a comprehensive program utilizing a large number of geophysical borehole methods has been carried out in 10 of these boreholes. The specific geophysical character of the rock mass and the major deformed units distinguished in the vicinity of the boreholes are recognized, and in certain cases also correlated between the boreholes. A general conclusion based on the geophysical logging results, made in this report, is that the preliminary predictions made in stage 2, of the site characterization and validation project (Olsson et.al, 1988), are adequate. The results from the geophysical logging can support the four predicted fracture/ fracture zones GHa, GHb, GA and GB whereas the predicted zones GC and GI are hard to confirm from the logging results. (author)

  17. Elemental logging in the KTB Pilot Hole. Pt. 1

    International Nuclear Information System (INIS)

    Grau, J.A.; Schweitzer, J.S.; Draxler, J.K.; Gatto, H.; Lauterjung, J.

    1993-01-01

    Neutron-induced γ-ray spectrometry, of prompt capture and delayed activation, together with natural γ-ray measurements, provide a borehole elemental analysis to characterize rock matrix composition. Elemental concentrations from the prompt capture measurements are derived through the use of a closure model that was developed from data on rocks in a sedimentary environment. This set of spectrometers was used to log the 4000 m of the German Continental Deep Drilling Project (KTB) Pilot Hole. The model was tested, with a minor change, for suitability to the crystalline rock environment. Good overall agreement was found between the logging measurements and laboratory analyses performed on cuttings and cores. (Author)

  18. Plataforma logística de Leixões

    OpenAIRE

    Pereira, Judite Filomena Soares

    2014-01-01

    Dissertação apresentada ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Logística Orientador: Prof. Doutor José António Baptista da Costa Coorientador: Engenheiro Artur Machado de Campos Rangel Nota: 16 valores O fenómeno da globalização nas economias contribui para as grandes alterações que se verificam nas redes e nas soluções de transporte e de abastecimento tornando-se assim cada vez mais importante o transporte integrado num conceito de Logística. ...

  19. Bayesian analysis of log Gaussian Cox processes for disease mapping

    DEFF Research Database (Denmark)

    Benes, Viktor; Bodlák, Karel; Møller, Jesper

    We consider a data set of locations where people in Central Bohemia have been infected by tick-borne encephalitis, and where population census data and covariates concerning vegetation and altitude are available. The aims are to estimate the risk map of the disease and to study the dependence...... of the risk on the covariates. Instead of using the common area level approaches we consider a Bayesian analysis for a log Gaussian Cox point process with covariates. Posterior characteristics for a discretized version of the log Gaussian Cox process are computed using markov chain Monte Carlo methods...

  20. Simultaneous thermal neutron decay time and porosity logging system

    International Nuclear Information System (INIS)

    Schultz, W.E.; Smith, H.D.; Smith, M.P.

    1980-01-01

    An improved method and apparatus are described for simultaneously measuring the porosity and thermal neutron capture cross section of earth formations in situ in the vicinity of a well borehole using pulsed neutron well logging techniques. The logging tool which is moved through the borehole consists of a 14 MeV pulsed neutron source, an epithermal neutron detector and a combination gamma ray and fast neutron detector. The associated gating systems, counters and combined digital computer are sited above ground. (U.K.)

  1. Advanced digital counting rate meter for gamma ray logging

    International Nuclear Information System (INIS)

    Kannan, S.; Meenakshi Sundari, A.; Rai, A.K.

    2013-01-01

    A compact, hand held controller based Advanced Digital Count Rate Meter (ADCRM) as a replacement of bulky Count Rate (analog) Meters (SBL-2A) was designed, developed and fabricated to carry out Gamma-Ray borehole logging with Geiger Muller (GM) tubes and Scintillation (SC) detectors. In the hardware the functionality of analog meter simulation, digital counting of gamma events and auto reference adjustment to use different length of armour cable winches were implemented. The in-built software evaluates grade in ppm and at the end of logging, the reports are prepared automatically. ADCRM was developed in-house to assist the uranium mineral exploration in AMD. (author)

  2. Error Checking for Chinese Query by Mining Web Log

    Directory of Open Access Journals (Sweden)

    Jianyong Duan

    2015-01-01

    Full Text Available For the search engine, error-input query is a common phenomenon. This paper uses web log as the training set for the query error checking. Through the n-gram language model that is trained by web log, the queries are analyzed and checked. Some features including query words and their number are introduced into the model. At the same time data smoothing algorithm is used to solve data sparseness problem. It will improve the overall accuracy of the n-gram model. The experimental results show that it is effective.

  3. Logging and Agricultural Residue Supply Curves for the Pacific Northwest

    Energy Technology Data Exchange (ETDEWEB)

    Kerstetter, James D.; Lyons, John Kim

    2001-01-01

    This report quantified the volume of logging residues at the county level for current timber harvests. The cost of recovering logging residues was determined for skidding, yearding, loading, chipping and transporting the residues. Supply curves were developed for ten candidate conversion sites in the Pacific Northwest Region. Agricultural field residues were also quantified at the county level using five-year average crop yields. Agronomic constraints were applied to arrive at the volumes available for energy use. Collection costs and transportation costs were determined and supply curves generated for thirteen candidate conversion sites.

  4. Log files as a tool for improving Internet dictionaries

    DEFF Research Database (Denmark)

    Henning, Bergenholtz.; Johnsen, Mia

    2005-01-01

    are not related to concrete examples of dictionary use. The surveys, which have always been concerned with printed dictionaries, have therefore not contributed to substantial improvements of dictionary conception. In the case of internet dictionaries, on the other hand, technical possibilities enable...... in the dictionary. Furthermore, log files allow lexicographers to see the types of information which have not, or not yet, been searched for. All in all, log files may thus be used as a tool for improving internet dictionaries - and perhaps also printed dictionaries - quite considerably....

  5. Clustering of users of digital libraries through log file analysis

    Directory of Open Access Journals (Sweden)

    Juan Antonio Martínez-Comeche

    2017-09-01

    Full Text Available This study analyzes how users perform information retrieval tasks when introducing queries to the Hispanic Digital Library. Clusters of users are differentiated based on their distinct information behavior. The study used the log files collected by the server over a year and different possible clustering algorithms are compared. The k-means algorithm is found to be a suitable clustering method for the analysis of large log files from digital libraries. In the case of the Hispanic Digital Library the results show three clusters of users and the characteristic information behavior of each group is described.

  6. A database for operation logging of the KEK photon factory

    International Nuclear Information System (INIS)

    Pak, C.O.

    1990-01-01

    A prototype database for operation logging of the KEK Photon Factory storage ring has been constructed and tested. This paper describes the basic design of the operation logging system and its performance. Front-end control computers gather various data concerning the operation of the storage ring, and transfer them to a large general-purpose computer through a token-ring network. We have adopted a relational database system so as to save large amounts of data under daily operation. An interactive software tool was developed to retrieve data and to make graphic representations easily. (orig.)

  7. Use of pulsed neutron-neutron logging, thermal neutron-neutron logging, and gamma logging methods in classification for sand-clay sediments of Lower Cretaceous in Prikumsk oil-and-gas region according to filtration-capacitance characteristics

    International Nuclear Information System (INIS)

    Maksimenko, A.N.; Basin, Ya.N.; Novgorodov, V.A.

    1974-01-01

    To isolate reservoirs, the formation and deformation penetration zone parameters are used. They are estimated according to the false oil saturation factor and the time of the penetration zone deformation which are determined from the complex exploration of cased wells using the pulse neutron logging, thermal neutron-neutron logging and gamma logging techniques

  8. Development of nuclear physics and its connections to borehole geophysics

    International Nuclear Information System (INIS)

    Loetzsch, W.

    1990-01-01

    Starting from the discovery of radioactivity, the development of nuclear physics and its close connections to geoscience, especially to borehole geophysics, are outlined. The discovery of a nuclear physical phenomenon is always followed by an examination for its applications in nuclear geophysics, which since about 1960 has developed into a special discipline of applied geophysics. As an example for this development in the GDR the application of neutron capture γ-ray spectroscopy for iron ore exploration is described. A table listing important present-day nuclear well logging techniques with detectable elements and their detection limits is presented. Examples of measurements with some of these logging techniques reveal their particularities and show their element-specific character and the nuclear physical mechanisms involved. Finally the state of art of nuclear well logging and prospects in this field are outlined. (author)

  9. Grading options for western hemlock "pulpwood" logs from southeastern Alaska.

    Science.gov (United States)

    David W. Green; Kent A. McDonald; John Dramm; Kenneth Kilborn

    Properties and grade yield are estimated for structural lumber produced from No. 3, No. 4, and low-end No. 2 grade western hemlock logs of the type previously used primarily for the production of pulp chips. Estimates are given for production in the Structural Framing, Machine Stress Rating, and Laminating Stock grading systems. The information shows that significant...

  10. Research on Producing Green Dimension Directly From Hardwood Logs

    Science.gov (United States)

    Philip A. Araman

    1995-01-01

    Because of rising timber costs and an increasing demand for high-grade timber, suppliers of solid wood products need additional material options. We feel that European and Japanese processing concepts of producing green dimension and other clear material directly from logs could provide an answer. In this paper we present a brief overview of our research results on...

  11. Water quality of some logged and unlogged California streams

    Science.gov (United States)

    Fredric R. Kopperdahl; James W. Burns; Gary E. Smith

    1971-01-01

    Water quality was monitored in 1968 and 1969 in six coastal streams in northern California, four of which were subjected to logging and/or road building (Bummer Lake Creek, South Fork Yager Creek, Little North Fork Noyo River, and South Fork Caspar Creek), while the others remained undisturbed (Godwood Creek and North Fork Caspar Creek). The purposes of this study were...

  12. Timber production in selectively logged tropical forests in South America.

    Science.gov (United States)

    Michael Keller; Gregory P. Asner; Geoffrey Blate; Frank McGlocklin; John Merry; Marielos Peña-Claros; Johan Zweede

    2007-01-01

    Selective logging is an extensive land-use practice in South America. Governments in the region have enacted policies to promote the establishment and maintenance of economically productive and sustainable forest industries.However, both biological and policy constraints threaten to limit the viability of the industry over the long term.Biological constraints, such as...

  13. An ecosystem model for tropical forest disturbance and selective logging

    Science.gov (United States)

    Maoyi Huang; Gregory P. Asner; Michael Keller; Joseph A. Berry

    2008-01-01

    [1] A new three-dimensional version of the Carnegie-Ames-Stanford Approach (CASA) ecosystem model (CASA-3D) was developed to simulate regional carbon cycling in tropical forest ecosystems after disturbances such as logging. CASA-3D has the following new features: (1) an alternative approach for calculating absorbed photosynthetically active radiation (APAR) using new...

  14. Predicting logging residues: an interim equation for Appalachian oak sawtimber

    Science.gov (United States)

    A. Jeff Martin

    1975-01-01

    An equation, using dbh, dbh², bole length, and sawlog height to predict the cubic-foot volume of logging residue per tree, was developed from data collected on 36 mixed oaks in southwestern Virginia. The equation produced reliable results for small sawtimber trees, but additional research is needed for other species, sites, and utilization practices.

  15. A logging residue "yield" table for Appalachian hardwoods

    Science.gov (United States)

    A. Jeff Martin

    1976-01-01

    An equation for predicting logging-residue volume per acre for Appalachian hardwoods was developed from data collected on 20 timber sales in national forests in West Virginia and Virginia. The independent variables of type-of-cut, products removed, basal area per acre, and stand age explained 95 percent of the variation in residue volume per acre. A "yield"...

  16. A first look at logging residue characteristics in West Virginia

    Science.gov (United States)

    A. Jeff Martin

    1975-01-01

    In 1973 and 1974, the Forest Products Marketing Laboratory obtained some preliminary information about characteristics of logging residues in West Virginia. Sixteen 1-acre plots were measured in conjunction with a test of the line-intersect sampling method. Findings from the 16 plots showed that hardwood residue volumes ranged from 100 to 1,300 cubic feet per acre,...

  17. Correlation between rotary drill performance parameters and borehole geophysical logging

    International Nuclear Information System (INIS)

    Scoble, M.J.; Peck, J.; Hendricks, C.

    1989-01-01

    There is a growing interest in developing performance monitoring techniques for both surface and underground mining equipment used in excavating, loading and transport systems. Research into the techniques and applications for monitoring drilling machinery including gamma and neutron logging, is reviewed. 17 refs.; 5 figs

  18. Forest Products: Apparatus for Removing Bark from Whole Logs

    International Nuclear Information System (INIS)

    Poole, Lauren; Recca, Lee

    1999-01-01

    Order this fact sheet now to learn how replacing the ''closed drum'' debarking technology method used in the forest industry with the ''open drum'' method saves time and production costs, and increases the economic value of wood products by inflicting less damage on logs so that they can be used for high-value economic products

  19. The impact of mechanical log surface damage on chip size ...

    African Journals Online (AJOL)

    Mechanised harvesting operations are becoming more prevalent in South Africa with the realisation that motormanual and manual harvesting operations pose significant health and safety risks to workers. The damage inflicted by single-grip harvester feed rollers and delimbing knives on log surfaces during debranching ...

  20. A new type of compensated neutron logging probe

    International Nuclear Information System (INIS)

    Ji Changsong; Shang Xiulan; Dai Zhude; Huang Heyi; Zhang Jianguo; Zu Shihuan; Zhao Jianqiang

    1988-01-01

    A new type of compensated neutron logging probe with glass scintillators has been designed. High sensitivity, long plateau and stability are the features of this probe which differs from the probes with 3 He or LiI(Eu) detector. From the results of field application the measured porosity is in good correspondence with the one obtained by rock core sampling method

  1. Longitudinal navigation log data on a large web domain

    NARCIS (Netherlands)

    Verberne, S.; Arends, B.; Kraaij, W.; Vries, A. de

    2016-01-01

    We have collected the access logs for our university's web domain over a time span of 4.5 years. We now release the pre-processed data of a 3-month period for research into user navigation behavior. We preprocessed the data so that only successful GET requests of web pages by non-bot users are kept.

  2. The Effect of Learning Log on the Academic Performance of ...

    African Journals Online (AJOL)

    The main intent of this study was to identify the impact of using learning log as a learning strategy on the academic performance of university students. Second year psychology students were included as subjects of this study. In the beginning of the study, the students were divided into two: experimental group (N = 60) and ...

  3. La logística y sus componentes

    Directory of Open Access Journals (Sweden)

    Deyanira Elizabeth Argumedo Sánchez

    2014-05-01

    Full Text Available Hoy en día el tema de la logística es un tema de suma importancia para las empresas ya que estas se han dado a la tarea de crear áreas especificas para su análisis se ha ido desarrollando a través del tiempo y en la actualidad se ha convertido en un aspecto de suma importancia para lograr que la empresa se posicione como del primer mundo. Antes se entendía como logística el tener el producto en el lugar indicado en el tiempo justo al menor costo posible pero ahora esas actividades han llegado a ser mejoradas que no solo se trata de eso ahora son todo un proceso. La logística determina y coordina en forma óptima el producto correcto, el cliente correcto, el tiempo y lugar correctos por lo tanto la logística no es una actividad funcional si no un modelo que permitirá reducir la incertidumbre de un futuro desconocido.

  4. Convergence of posteriors for discretized log Gaussian Cox processes

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus Plenge

    2004-01-01

    In Markov chain Monte Carlo posterior computation for log Gaussian Cox processes (LGCPs) a discretization of the continuously indexed Gaussian field is required. It is demonstrated that approximate posterior expectations computed from discretized LGCPs converge to the exact posterior expectations...... when the cell sizes of the discretization tends to zero. The effect of discretization is studied in a data example....

  5. Research on the utilization of logging residues in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Hakkila, P

    1970-01-01

    This report describes Scandinavian research projects set up in 1969, under Finnish direction, on the utilization of logging residues. The project includes five studies on the utilization of branch-wood and five on stump- and root-wood, which are being carried out by various institutes.

  6. Testing and analysis of internal hardwood log defect prediction models

    Science.gov (United States)

    R. Edward Thomas

    2011-01-01

    The severity and location of internal defects determine the quality and value of lumber sawn from hardwood logs. Models have been developed to predict the size and position of internal defects based on external defect indicator measurements. These models were shown to predict approximately 80% of all internal knots based on external knot indicators. However, the size...

  7. Cross-system log file analysis for hypothesis testing

    NARCIS (Netherlands)

    Glahn, Christian; Specht, Marcus; Schoonenboom, Judith; Sligte, Henk; Moghnieh, Ayman; Hernández-Leo, Davinia; Stefanov, Krassen; Lemmers, Ruud; Koper, Rob

    2008-01-01

    Glahn, C., Specht, M., Schoonenboom, J., Sligte, H., Moghnieh, A., Hernández-Leo, D. Stefanov, K., Lemmers, R., & Koper, R. (2008). Cross-system log file analysis for hypothesis testing. In H. Sligte & R. Koper (Eds.), Proceedings of the 4th TENCompetence Open Workshop. Empowering Learners for

  8. Madagascar rosewood, illegal logging and the tropical timber trade ...

    African Journals Online (AJOL)

    Although deforestation rates in the tropics are reportedly slowing, the loss of both forest area and forest quality remains a significant issue for many countries. This is particularly true of Madagascar, where recent government instability has enabled a significant increase in the incidence of illegal logging of Dalbergia species ...

  9. Effect of Logging Activities on Water Quality and Benthic ...

    African Journals Online (AJOL)

    The study was conducted to determine the effect of logging activities on water quality and benthic macroinvertebrate assemblages for the Madek River basin. The study area was situated in Kluang, Johor, Malaysia. Two sampling stations 500 meters apart are upstream and the other, downstream located at Madek River ...

  10. Validation of an internal hardwood log defect prediction model

    Science.gov (United States)

    R. Edward. Thomas

    2011-01-01

    The type, size, and location of internal defects dictate the grade and value of lumber sawn from hardwood logs. However, acquiring internal defect knowledge with x-ray/computed-tomography or magnetic-resonance imaging technology can be expensive both in time and cost. An alternative approach uses prediction models based on correlations among external defect indicators...

  11. Log-fueled boilers; Les chaudieres a buches

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This document describes the different technologies of wood boilers fueled with logs (ascending combustion and natural draught, horizontal combustion and natural draught, reverse combustion and natural draught, reverse combustion and forced draught), their advantages and drawbacks, selection criteria and installation rules. (J.S.)

  12. Comparison between moving and stationary transmitter systems in induction logging

    Science.gov (United States)

    Poddar, M.; Caleb Dhanasekaran, P.; Prabhakar Rao, K.

    1985-09-01

    In a general treatment of the theory of induction logging, an exact integral representation has been obtained for the mutual impedance between a vertical dipole transmitter and a coaxial dipole receiver in a three layered earth. Based on this representation, a computer model has been devised using the traditional Slingram system of induction logging and the comparatively new Turam system, ignoring borehole effects. The model results indicate that due to its much larger response, the Turam system is in general preferable to the Slingram in mineral and groundwater investigations where formation conductivity much less than 1 S/m is generally encountered. However, if the surrounding media are conductive (more than 0.1 S/m), the Turam system suffers from large amplitude attenuation and phase rotation of the primary field caused by the conductive surrounding, and is less useful than the Slingram system which does not so suffer, unless the target bed is shallow. Because it is a more complex function of system parameters than the corresponding Slingram log, a Turam log can be conveniently interpreted only by the modern inverse method using a fast algorithm for the forward solution and a high speed digital computer.

  13. Estimating two indirect logging costs caused by accelerated erosion.

    Science.gov (United States)

    Glen O. Klock

    1976-01-01

    In forest areas where high soil erosion potential exists, a comparative yarding cost estimate, including the indirect costs determined by methods proposed here, shows that the total cost of using "advanced" logging methods may be less than that of "traditional" systems.

  14. A Comparative Study of Cox Regression vs. Log-Logistic ...

    African Journals Online (AJOL)

    Colorectal cancer is common and lethal disease with different incidence rate in different parts of the world which is taken into account as the third cause of cancer-related deaths. In the present study, using non-parametric Cox model and parametric Log-logistic model, factors influencing survival of patients with colorectal ...

  15. Clonal differences in log end splitting in Eucalyptus grandis in ...

    African Journals Online (AJOL)

    This paper discusses the juvenile–mature correlation of log end splitting among Eucalyptus grandis clones from two trials and how differences in splitting relate to differences in wood density, pith-to-bark gradient and growth rate. Two approximately 20-year-old Eucalyptus grandis clonal trials at Bergvliet plantation were ...

  16. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Kishore K. Mohanty

    2005-09-05

    The objective of this report is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity. Oil based drilling fluids can have an adverse effect on NMR well logging if it alters the wettability of the formation. The effect of various surfactants on wettability and surface relaxivity are evaluated for silica sand. The relation between the relaxation time and diffusivity distinguishes the response of brine, oil, and gas in a NMR well log. A new NMR pulse sequence in the presence of a field gradient and a new inversion technique enables the T{sub 2} and diffusivity distributions to be displayed as a two-dimensional map. The objectives of pore morphology and rock characterization are to identify vug connectivity by using X-ray CT scan, and to improve NMR permeability correlation. Improved estimation of permeability from NMR response is possible by using estimated tortuosity as a parameter to interpolate between two existing permeability models.

  17. Well-log based prediction of thermal conductivity

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea

    Rock thermal conductivity (TC) is paramount for the determination of heat flow and the calculation of temperature profiles. Due to the scarcity of drill cores compared to the availability of petrophysical well logs, methods are desired to indirectly predict TC in sedimentary basins. Most...

  18. Log sampling methods and software for stand and landscape analyses.

    Science.gov (United States)

    Lisa J. Bate; Torolf R. Torgersen; Michael J. Wisdom; Edward O. Garton; Shawn C. Clabough

    2008-01-01

    We describe methods for efficient, accurate sampling of logs at landscape and stand scales to estimate density, total length, cover, volume, and weight. Our methods focus on optimizing the sampling effort by choosing an appropriate sampling method and transect length for specific forest conditions and objectives. Sampling methods include the line-intersect method and...

  19. Monitoring selective logging in western Amazonia with repeat lidar flights

    Science.gov (United States)

    H.E. Andersen; S.E. Reutebuch; R.J. McGaughey; M.V.N. d' Oliveira; M. Keller

    2014-01-01

    The objective of this study was to test the use of repeat flight, airborne laser scanning data (lidar) for estimating changes associated with low-impact selective logging (approx. 10-15 m3 ha−1 = 5-7% of total standing volume harvested) in natural tropical forests in the Western Brazilian Amazon. Specifically, we investigated change in area...

  20. Acoustic measurements on trees and logs: a review and analysis

    Science.gov (United States)

    Xiping Wang

    2013-01-01

    Acoustic technologies have been well established as material evaluation tools in the past several decades, and their use has become widely accepted in the forest products industry for online quality control and products grading. Recent research developments on acoustic sensing technology offer further opportunities to evaluate standing trees and logs for general wood...

  1. Carbon emissions from tropical forest degradation caused by logging

    International Nuclear Information System (INIS)

    Pearson, Timothy R H; Brown, Sandra; Casarim, Felipe M

    2014-01-01

    The focus of land-use related efforts in developing countries to reduce carbon emissions has been on slowing deforestation, yet international agreements are to reduce emissions from both deforestation and forest degradation (REDD). The second ‘D’ is poorly understood and accounted for a number of technical and policy reasons. Here we introduce a complete accounting method for estimating emission factors from selective timber harvesting, a substantial form of forest degradation in many tropical developing countries. The method accounts separately for emissions from the extracted log, from incidental damage to the surrounding forest, and from logging infrastructure, and emissions are expressed as units of carbon per cubic meter of timber extracted to allow for simple application to timber harvesting statistics. We applied the method in six tropical countries (Belize, Bolivia, Brazil, Guyana, Indonesia, and Republic of Congo), resulting in total emission factors of 0.99−2.33 Mg C m −3 . In all cases, emissions were dominated by damage to surrounding vegetation and the infrastructure rather than the logs themselves, and total emissions represented about 3–15% of the biomass carbon stocks of the associated unlogged forests. We then combined the emission factors with country level logging statistics for nine key timber producing countries represented by our study areas to gain an understanding of the order of magnitude of emissions from degradation compared to those recently reported for deforestation in the same countries. For the nine countries included, emissions from logging were on average equivalent to about 12% of those from deforestation. For those nine countries with relatively low emissions from deforestation, emissions from logging were equivalent to half or more of those from deforestation, whereas for those countries with the highest emissions from deforestation, emissions from logging were equivalent to <10% of those from deforestation

  2. Carbon emissions performance of commercial logging in East Kalimantan, Indonesia.

    Science.gov (United States)

    Griscom, Bronson; Ellis, Peter; Putz, Francis E

    2014-03-01

    Adoption of reduced-impact logging (RIL) methods could reduce CO2 emissions by 30-50% across at least 20% of remaining tropical forests. We developed two cost effective and robust indices for comparing the climate benefits (reduced CO2 emissions) due to RIL. The indices correct for variability in the volume of commercial timber among concessions. We determined that a correction for variability in terrain slope was not needed. We found that concessions certified by the Forest Stewardship Council (FSC, N = 3), when compared with noncertified concessions (N = 6), did not have lower overall CO2 emissions from logging activity (felling, skidding, and hauling). On the other hand, FSC certified concessions did have lower emissions from one type of logging impact (skidding), and we found evidence of a range of improved practices using other field metrics. One explanation of these results may be that FSC criteria and indicators, and associated RIL practices, were not designed to achieve overall emissions reductions. Also, commonly used field metrics are not reliable proxies for overall logging emissions performance. Furthermore, the simple distinction between certified and noncertified concessions does not fully represent the complex history of investments in improved logging practices. To clarify the relationship between RIL and emissions reductions, we propose the more explicit term 'RIL-C' to refer to the subset of RIL practices that can be defined by quantified thresholds and that result in measurable emissions reductions. If tropical forest certification is to be linked with CO2 emissions reductions, certification standards need to explicitly require RIL-C practices. © 2013 John Wiley & Sons Ltd.

  3. Combined Log Inventory and Process Simulation Models for the Planning and Control of Sawmill Operations

    Science.gov (United States)

    Guillermo A. Mendoza; Roger J. Meimban; Philip A. Araman; William G. Luppold

    1991-01-01

    A log inventory model and a real-time hardwood process simulation model were developed and combined into an integrated production planning and control system for hardwood sawmills. The log inventory model was designed to monitor and periodically update the status of the logs in the log yard. The process simulation model was designed to estimate various sawmill...

  4. Nuclear Medicine

    Science.gov (United States)

    ... Parents/Teachers Resource Links for Students Glossary Nuclear Medicine What is nuclear medicine? What are radioactive tracers? ... funded researchers advancing nuclear medicine? What is nuclear medicine? Nuclear medicine is a medical specialty that uses ...

  5. Method and apparatus for producing a porosity log of a subsurface formation corrected for detector standoff

    International Nuclear Information System (INIS)

    Allen, L.S.; Leland, F.P.; Lyle, W.D. Jr.; Stromswold, D.C.

    1993-01-01

    A borehole logging tool with a pulsed source of fast neutrons is lowered into a borehole traversing a subsurface formation, and a neutron detector measures the die-away of nuclear radiation in the formation. A model of the die-away is produced using exponential terms varying as the sum of borehole, formation and thermal neutron background components. Exponentially weighted moments of both the die-away measurements and a model are determined and equated. The formation decay constant is determined from the formation and thermal neutron background. An epithermal neutron lifetime is determined from the formation decay constant and is used with the amplitude ratio by a trained neural network to determine a lifetime correction. A standoff corrected lifetime is determined from the epithermal neutron lifetime and the lifetime correction. (author)

  6. Geophysical borehole logging and optical imaging of the pilot hole ONK-PH2

    International Nuclear Information System (INIS)

    Lahti, M.; Heikkinen, E.

    2005-01-01

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of pilot hole ONK-PH2 in ONKALO tunnel at the Olkiluoto site in December 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all the surveys, integration of the data as well as interpretation of the acoustic and borehole radar data. The report describes the field operation, equipment, processing procedures, interpretation results and shows the obtained geophysical and image data. The data as well as the interpretation results are delivered digitally in WellCAD and Excel format. (orig.)

  7. Geophysical borehole logging and optical imaging of the pilot hole ONK-PH2

    Energy Technology Data Exchange (ETDEWEB)

    Lahti, M. [Suomen Malmi Oy, Espoo (Finland); Heikkinen, E. [JP-Fintact Oy, Vantaa (Finland)

    2005-01-15

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of pilot hole ONK-PH2 in ONKALO tunnel at the Olkiluoto site in December 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all the surveys, integration of the data as well as interpretation of the acoustic and borehole radar data. The report describes the field operation, equipment, processing procedures, interpretation results and shows the obtained geophysical and image data. The data as well as the interpretation results are delivered digitally in WellCAD and Excel format. (orig.)

  8. A new philosophy for calibrating oil well logging tools based on neutron transport codes

    International Nuclear Information System (INIS)

    Butler, J.; Clayton, C.G.

    1984-01-01

    The current practice of calibrating neutron borehole logging probes is limited by an inability to match calibration conditions to those which pertain in an operational situation. In addition, test boreholes are expensive to construct and, when natural materials are used, rely on an exact correspondence in composition and in structure between the materials of the test facility and representative samples which may not be valid. Now that neutron tansport codes have been developed to a point at which they are able to cope with realistic, complex situations an alternative approach to calibration can be considered. The basis of this philosophy is the construction of a limited number of calibration facilities which are composed of artificial rocks of controlled but variable porosity and accurately known nuclear characteristics

  9. Nuclear safety. Seguranca nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Aveline, A [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica

    1981-01-01

    What is nuclear safety Is there any technical way to reduce risks Is it possible to put them at reasonable levels Are there competitiveness and economic reliability to employ the nuclear energy by means of safety technics Looking for answers to these questions the author describes the sources of potential risks to nuclear reactors and tries to apply the answers to the Brazilian Nuclear Programme. (author).

  10. High-resolution well-log derived dielectric properties of gas-hydrate-bearing sediments, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Science.gov (United States)

    Sun, Y.; Goldberg, D.; Collett, T.; Hunter, R.

    2011-01-01

    A dielectric logging tool, electromagnetic propagation tool (EPT), was deployed in 2007 in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert Well), North Slope, Alaska. The measured dielectric properties in the Mount Elbert well, combined with density log measurements, result in a vertical high-resolution (cm-scale) estimate of gas hydrate saturation. Two hydrate-bearing sand reservoirs about 20 m thick were identified using the EPT log and exhibited gas-hydrate saturation estimates ranging from 45% to 85%. In hydrate-bearing zones where variation of hole size and oil-based mud invasion are minimal, EPT-based gas hydrate saturation estimates on average agree well with lower vertical resolution estimates from the nuclear magnetic resonance logs; however, saturation and porosity estimates based on EPT logs are not reliable in intervals with substantial variations in borehole diameter and oil-based invasion.EPT log interpretation reveals many thin-bedded layers at various depths, both above and below the thick continuous hydrate occurrences, which range from 30-cm to about 1-m thick. Such thin layers are not indicated in other well logs, or from the visual observation of core, with the exception of the image log recorded by the oil-base microimager. We also observe that EPT dielectric measurements can be used to accurately detect fine-scale changes in lithology and pore fluid properties of hydrate-bearing sediments where variation of hole size is minimal. EPT measurements may thus provide high-resolution in-situ hydrate saturation estimates for comparison and calibration with laboratory analysis. ?? 2010 Elsevier Ltd.

  11. Invisible nuclear; converting nuclear

    International Nuclear Information System (INIS)

    Park, Jongmoon

    1993-03-01

    This book consists of 14 chapters which are CNN era and big science, from East and West to North and South, illusory nuclear strategy, UN and nuclear arms reduction, management of armaments, advent of petroleum period, the track of nuclear power generation, view of energy, internationalization of environment, the war over water in the Middle East, influence of radiation and an isotope technology transfer and transfer armament into civilian industry, the end of nuclear period and the nuclear Nonproliferation, national scientific and technological power and political organ and executive organ.

  12. Log-ratio circuit for beam position monitoring

    International Nuclear Information System (INIS)

    Wells, F.D.; Shafer, R.E.; Gilpatrick, J.D.; Shurter, R.B.

    1990-01-01

    A synopsis is given of work in progress on a new signal processing technique for obtaining real-time normalized beam position information from sensing electrodes in accelerator beam pipes. The circuit employs wideband logarithmic amplifiers in a configuration that converts pickup electrode signals to position signals that are substantially independent of beam current. The circuit functions as a ratio detector that computes the logarithm of (A/B) as (Log A-Log B), and presents the result in a video (real-time analog) format representing beam position. It has potential benefits of greater dynamic range and better linearity than other techniques currently used and it may be able to operate at substantially higher frequencies. 4 refs., 8 figs

  13. Borehole Logging for Uranium by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Nyegaard, P.; Christiansen, E. M.

    1980-01-01

    The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium-iodide, and the photo......The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium...... of the spectrometer system were determined by calculating the average number of U and thorium (Th) counts per meter of borehole and comparing these with the U-Th concentrations in 1-m sections of analyzed drill core. The sensitivity and the background count rate in the uranium window varied appreciably from one hole...

  14. System for gamma-gamma formation density logging while drilling

    International Nuclear Information System (INIS)

    Paske, W.C.

    1991-01-01

    The patent relates to a system for logging subterranean formations for the determination of formation density by using gamma radiation. Gamma ray source and detection means are disposed within a housing adapted for positioning within a borehole for the emission and detection of gamma rays propagating through earth formations and borehole drilling fluid. The gamma ray detection means comprises first and second gamma radiation sensors geometrically disposed within the housing, the same longitudinal distance from the gamma ray source and diametrically opposed in a common plane. A formation matrix density output signal is produced in proportion to the output signal from each of the gamma ray sensors and in conjunction with certain constants established by the geometrical configuration of the sensors relative to the gamma ray source and the borehole diameter. Formation density is determined without regard to the radial position of the logging probe within the borehole in a measuring while drilling mode. 6 figs

  15. Logging while drilling keeps horizontal well on small target

    International Nuclear Information System (INIS)

    Leake, J.; Shray, F.

    1991-01-01

    This paper reports that the logging-while-drilling (LWD) measurement to two resistivities of different characteristics had led to a new interpretation method for the analysis of horizontal wells. By logging deep and shallow resistivity in real-time, marker beds were identified to help maintain well bore trajectory. The resistivity measurements were split into vertical and horizontal components to provide additional information of formation evaluation. In 1945, Ark Fuel Co. discovered and began developing the Olla field on the crest of the La Salle arch in La Salle Parish, La. Oil production comes from the Wilcox formation from alluvial sand packages that range in thickness from 3 ft to 120 ft. Now operated by Oxy U.S.A. Inc., Olla field was chosen in 1990 for a horizontal well pilot project. It was hoped that a horizontal well could alleviate water coming in one of the field's more productive sand packages- the 40-ft Cruse sand

  16. Novel Desorber for Online Drilling Mud Gas Logging.

    Science.gov (United States)

    Lackowski, Marcin; Tobiszewski, Marek; Namieśnik, Jacek

    2016-01-01

    This work presents the construction solution and experimental results of a novel desorber for online drilling mud gas logging. The traditional desorbers use mechanical mixing of the liquid to stimulate transfer of hydrocarbons to the gaseous phase that is further analyzed. The presented approach is based on transfer of hydrocarbons from the liquid to the gas bubbles flowing through it and further gas analysis. The desorber was checked for gas logging from four different drilling muds collected from Polish boreholes. The results of optimization studies are also presented in this study. The comparison of the novel desorber with a commercial one reveals strong advantages of the novel one. It is characterized by much better hydrocarbons recovery efficiency and allows reaching lower limits of detection of the whole analytical system. The presented desorber seems to be very attractive alternative over widely used mechanical desorbers.

  17. Novel Desorber for Online Drilling Mud Gas Logging

    Directory of Open Access Journals (Sweden)

    Marcin Lackowski

    2016-01-01

    Full Text Available This work presents the construction solution and experimental results of a novel desorber for online drilling mud gas logging. The traditional desorbers use mechanical mixing of the liquid to stimulate transfer of hydrocarbons to the gaseous phase that is further analyzed. The presented approach is based on transfer of hydrocarbons from the liquid to the gas bubbles flowing through it and further gas analysis. The desorber was checked for gas logging from four different drilling muds collected from Polish boreholes. The results of optimization studies are also presented in this study. The comparison of the novel desorber with a commercial one reveals strong advantages of the novel one. It is characterized by much better hydrocarbons recovery efficiency and allows reaching lower limits of detection of the whole analytical system. The presented desorber seems to be very attractive alternative over widely used mechanical desorbers.

  18. Geophysical logging for groundwater investigations in Southern Thailand

    Directory of Open Access Journals (Sweden)

    Phongpiyah Klinmanee

    2012-09-01

    Full Text Available In Thailand the Department of Groundwater Resources is drilling to find vital aquifers. Sometimes groundwater formations cannot be identified clearly during drilling; therefore, geophysical logging was applied after drilling and before casing.The tool used here is measuring nine parameters in one run, natural gamma ray, spontaneous potential, single point resistance, normal resistivity (AM 8’’, 16’’, 32’’, and 64’’, mud temperature and resistivity. Cutting was used to support the geophysical interpretations. In many cases the groundwater bearing zones could be clearly identified. The combination of andthe possibility choosing from nine parameters measured provided the necessary data base to identify groundwater bearingzones in different environments. It has been demonstrated that in different wells different tools are favorable than others.Based on the conclusions of this study geophysical logging in groundwater exploration is recommended as a normalstandard technique that should be applied in every new well drilled.

  19. A new measurement-while-drilling gamma ray log calibrator

    International Nuclear Information System (INIS)

    Meisner, J.; Brooks, A.; Wisniewski, W.

    1985-01-01

    Many of the present methods of calibration for both wireline and MWD gamma ray detectors use a point source at a fixed distance from the detector. MWD calibration errors are introduced from scattering effects, from spectral differences, from position sensitivity and form lack of cylindrical geometry. A new method has been developed at Exploration Logging INc. (EXLOG) that eliminates these errors. The method uses a wrap-around or annular calibrator, referenced to the University of Houston gamma ray API pit. The new calibrator is designed to simulate the API pit's gamma ray emission spectrum with a finite amount of natural source material in the annular shape. Because of the thickness of steel between the MWD gamma ray detector and the formation, there is theoretical necessity for spectral matching. A simple theoretical approach was used to calibrate the new calibrator. Spectral matching allows a closer approximation to wireline logs and makes it possible to estimate the relative spectral content of a formation

  20. Design of a transport calculation system for logging sondes simulation

    International Nuclear Information System (INIS)

    Marquez Damian, Jose Ignacio

    2005-01-01

    Analysis of available resources in earth crust is performed by different techniques, one of them is neutron logging. Design of sondes that are used to make such logging is supported by laboratory experiments as well as by numerical calculations.This work presents several calculation schemes, designed to simplify the task of whom has to planify such experiments or optimize parameters of this kind of sondes.These schemes use transport calculation codes, especially DaRT, TORT and MCNP, and cross section processing modules from SCALE system.Additionally a system for DaRT and TORT data postprocessing using OpenDX is presented.It allows scalar flux spatial distribution analysis, as wells as cross section condensation and reaction rates calculation

  1. Preclinical tests of an android based dietary logging application.

    Science.gov (United States)

    Kósa, István; Vassányi, István; Pintér, Balázs; Nemes, Márta; Kámánné, Krisztina; Kohut, László

    2014-01-01

    The paper describes the first, preclinical evaluation of a dietary logging application developed at the University of Pannonia, Hungary. The mobile user interface is briefly introduced. The three evaluation phases examined the completeness and contents of the dietary database and the time expenditure of the mobile based diet logging procedure. The results show that although there are substantial individual differences between various dietary databases, the expectable difference with respect to nutrient contents is below 10% on typical institutional menu list. Another important finding is that the time needed to record the meals can be reduced to about 3 minutes daily especially if the user uses set-based search. a well designed user interface on a mobile device is a viable and reliable way for a personalized lifestyle support service.

  2. Methods and apparatus for environmental correction of thermal neutron logs

    International Nuclear Information System (INIS)

    Preeg, W.E.; Scott, H.D.

    1983-01-01

    An on-line environmentally-corrected measurement of the thermal neutron decay time (tau) of an earth formation traversed by a borehole is provided in a two-detector, pulsed neutron logging tool, by measuring tau at each detector and combining the two tau measurements in accordance with a previously established empirical relationship of the general form: tau = tausub(F) +A(tausub(F) + tausub(N)B) + C, where tausub(F) and tausub(N) are the tau measurements at the far-spaced and near-spaced detectors, respectively, A is a correction coefficient for borehole capture cross section effects, B is a correction coefficient for neutron diffusion effects, and C is a constant related to parameters of the logging tool. Preferred numerical values of A, B and C are disclosed, and a relationship for more accurately approximating the A term to specific borehole conditions. (author)

  3. Geophysical borehole logging. Final disposal of spent fuel

    International Nuclear Information System (INIS)

    Rouhiainen, P.

    1984-01-01

    Teollisuuden Voima Oy (Industrial Power Company Ltd.) will take precautions for final disposal of spent fuel in the Finnish bedrock. The first stage of the site selection studies includes drilling of a deep borehole down to approximately 1000 meters in the year 1984. The report deals with geophysical borehole logging methods, which could be used for the studies. The aim of geophysical borehole logging methods is to descripe specially hydrogeological and structural features. Only the most essential methods are dealt with in this report. Attention is paid to the information produced with the methods, derscription of the methods, interpretation and limitations. The feasibility and possibilities for the aims are evaluated. The evaluations are based mainly on the results from Sweden, England, Canada and USA as well as experiencies gained in Finland

  4. Combination thermal and radiation shield for well logging apparatus

    International Nuclear Information System (INIS)

    Wilson, B.F.

    1984-01-01

    A device for providing both thermal protection and radiation shielding for components such as radiation detectors within a well logging instrument comprises a thermally insulative flask containing a weldment filled with a mass of eutectic material which undergoes a change of state e.g. melting at a temperature which will provide an acceptable thermal environment for such components for extended time periods. The eutectic material which is preferably a bismuth (58%)/tin (42%) alloy has a specific gravity (> 8.5) facilitating its use as a radiation shield and is distributed around the radiation detectors so as to selectively impede the impinging of the detectors by radiation. The device is incorporated in a skid of a well logging instrument for measuring γ backscatter. A γ source is located either above or within the protective shielding. (author)

  5. Log bioassay of residual effectiveness of insecticides against bark beetles

    Science.gov (United States)

    Richard H. Smith

    1982-01-01

    Residual effectiveness of nine insecticides applied to bark was tested against western, mountain, and Jeffrey pine beetles. Ponderosa and Jeffrey pine trees were treated and logs cut from them 2 to 13 months later, and bioassayed with the three beetles. The insecticides were sprayed at the rate of 1 gal (3.8 l) per 40- or 80-ft² (3.6 or 7.2 m²) bark surface at varying...

  6. Necromass in undisturbed and logged forests in the Brazilian Amazon.

    Science.gov (United States)

    Michael Palace; Michael Keller; Gregory P. Asner; Jose Natalino M. Silva; Carlos. Passos

    2007-01-01

    Necromass is an important stock of carbon in tropical forests. We estimated volume, density, and mass of fallen and standing necromass in undisturbed and selectively logged forests at Juruena, Mato Grosso, Brazil (10.488S, 58.478W). We also measured standing dead trees at the Tapajos National Forest, Para, Brazil (3.088S, 54.948W) complementing our earlier study there...

  7. Message Correlation for Conversation Reconstruction in Service Interaction Logs

    OpenAIRE

    Motahari Nezhad, Hamid R.; Saint-Paul, Regis; Benatallah, Boualem; Casati, Fabio; Andritsos, Periklis

    2007-01-01

    The problem of understanding the behavior of business processes and of services is rapidly becoming a priority in medium and large companies. To this end, recently, analysis tools as well as variations of data mining techniques have been applied to process and service execution logs to perform OLAP-style analysis and to discover behavioral (process and protocol) models out of execution data. All these approaches are based on one key assumption: events describing executions and stored in proce...

  8. Deformation of log-likelihood loss function for multiclass boosting.

    Science.gov (United States)

    Kanamori, Takafumi

    2010-09-01

    The purpose of this paper is to study loss functions in multiclass classification. In classification problems, the decision function is estimated by minimizing an empirical loss function, and then, the output label is predicted by using the estimated decision function. We propose a class of loss functions which is obtained by a deformation of the log-likelihood loss function. There are four main reasons why we focus on the deformed log-likelihood loss function: (1) this is a class of loss functions which has not been deeply investigated so far, (2) in terms of computation, a boosting algorithm with a pseudo-loss is available to minimize the proposed loss function, (3) the proposed loss functions provide a clear correspondence between the decision functions and conditional probabilities of output labels, (4) the proposed loss functions satisfy the statistical consistency of the classification error rate which is a desirable property in classification problems. Based on (3), we show that the deformed log-likelihood loss provides a model of mislabeling which is useful as a statistical model of medical diagnostics. We also propose a robust loss function against outliers in multiclass classification based on our approach. The robust loss function is a natural extension of the existing robust loss function for binary classification. A model of mislabeling and a robust loss function are useful to cope with noisy data. Some numerical studies are presented to show the robustness of the proposed loss function. A mathematical characterization of the deformed log-likelihood loss function is also presented. Copyright 2010 Elsevier Ltd. All rights reserved.

  9. Hydrocarbon type identification with MWD neutron porosity logging

    International Nuclear Information System (INIS)

    Simms, G.J.; Koopersmith, C.A.

    1991-01-01

    This paper reports on measurement-while-drilling (MWD) information which accurately defined gas, oil, and water in an offshore field. Basic MWD and wireline formation evaluation data compare favorably. A cost saving of $120,000 was realized when MWD information was used instead of wireline data on one well. In the future, MWD logs may serve as the primary evaluation data on routine development wells in similar fields

  10. Logging technique for assaying for uranium in earth formations

    International Nuclear Information System (INIS)

    Givens, W.W.; Mills, W.R. Jr.

    1979-01-01

    A borehole logging tool includes a source of fast neutrons, an epithermal neutron flux detector, and a thermal neutron flux detector. A count rate meter is connected to each detector. A ratio detector provides a signal indicative of the ratio of the count rates of the two detectors obtained during the time that prompt neutrons are emitted from neutron fission of uranium in the formation

  11. Log-Optimal Portfolio Selection Using the Blackwell Approachability Theorem

    OpenAIRE

    V'yugin, Vladimir

    2014-01-01

    We present a method for constructing the log-optimal portfolio using the well-calibrated forecasts of market values. Dawid's notion of calibration and the Blackwell approachability theorem are used for computing well-calibrated forecasts. We select a portfolio using this "artificial" probability distribution of market values. Our portfolio performs asymptotically at least as well as any stationary portfolio that redistributes the investment at each round using a continuous function of side in...

  12. Using data logging to measure Young’s modulus

    Science.gov (United States)

    Richardson, David

    2018-03-01

    Historically the Young’s modulus of a material is measured by increasing the applied force to a wire and measuring the extension. The cross sectional area and original length allow this to be plotted as a graph of stress versus strain. This article describes how data logging sensors can be used to measure how the force changes with extension, allowing a strain versus stress graph to be plotted into the region of plastic deformation.

  13. Continuous Tamper-proof Logging using TPM2.0

    Science.gov (United States)

    2014-06-16

    process each log entry. Additional hardware support could mitigate this problem. Tradeoffs between performance and security guarantees Disk write...becomes weaker as the block size increases. This problem is mitigated in protocol B by allowing offline recovery from a power failure and detection of...M.K., Isozaki, H.: Flicker : An execution infrastructure for TCB minimization. ACM SIGOPS Operating Systems Review 42(4) (2008) 315–328 24. Parno, B

  14. Audit and trace log management consolidation and analysis

    CERN Document Server

    Maier, Phillip Q

    2006-01-01

    As regulation and legislation evolve, the critical need for cost-effective and efficient IT audit and monitoring solutions will continue to grow. Audit and Trace Log Management: Consolidation and Analysis offers a comprehensive introduction and explanation of requirements and problem definition, and also delivers a multidimensional solution set with broad applicability across a wide range of organizations. Itprovidesa wealth of information in the form of processwalkthroughs. These include problem determination, requirements gathering,scope definition, risk assessment, compliance objectives,

  15. Modeling the dielectric logging tool at high frequency

    International Nuclear Information System (INIS)

    Chew, W.C.

    1987-01-01

    The high frequency dielectric logging tool has been used widely in electromagnetic well logging, because by measuring the dielectric constant at high frequencies (1 GHz), the water saturation of rocks could be known without measuring the water salinity in the rocks. As such, it could be used to delineate fresh water bearing zones, as the dielectric constant of fresh water is much higher than that of oil while they may have the same resistivity. The authors present a computer model, though electromagnetic field analysis, the response of such a measurement tool in a well logging environment. As the measurement is performed at high frequency, usually with small separation between the transmitter and receivers, some small geological features could be measured by such a tool. They use the computer model to study the behavior of such a tool across geological bed boundaries, and also across thin geological beds. Such a study could be very useful in understanding the limitation on the resolution of the tool. Furthermore, they could study the standoff effect and the depth of investigation of such a tool. This could delineate the range of usefulness of the measurement

  16. Use of activity logs to improve online collaboration

    Directory of Open Access Journals (Sweden)

    César Coll Salvador

    2018-02-01

    Full Text Available This article presents a review of works that center their interest in eLearning platforms and the data mining of participants’ activity. The studies in this research area generate information, through the analysis of such logs and data, that is provided to the students in real time to help them to collaborate and learn through collaboration on the platform. There are studies from different areas of study such as Learning Analytics, Educational Data Mining, Group Awareness Tools or Interaction Analysis Tools. The review takes a double perspective: i to analyze the data extracted from activity logs, their processing, the information generated and the ways to communicate it; and ii to explorer the model and the instruments used to assess how the information provided impact on online collaborative processes and/or the learning. The conclusions emphasize that the models of collaborative learning that justifies the selection of the data extracted from the activity logs, the processing, the information generated and provided to the students and the way of communicating it, are not explicitly stated. In addition, important biases are detected because of not considering the multidimensional nature of the collaborative learning processes. Also, few studies analyze the relations between students' uses of the information provided and the quality of their collaborative processes and learning results. The very few studies that do analyze such relation do not go into depth on the changes in group dynamics caused by information.

  17. Log evaluation of sub-bituminous coals in Magallanes, Chile

    International Nuclear Information System (INIS)

    Weltz, L.S.

    1976-01-01

    In coal exploration a drilling program is normally used for coal inquest through core analysis, with a high cost and operating time. However, in many cases, there is poor cores recovery due to operating procedures and/or formation conditions which leads to the determination of parameters non-representative of the coal seam. The cost and operating time can be minimized through the use of logs which also represent a continuous and in situ sampling. In the case of sub-bituminous coals, the analysis through logs is more complex due to the high content of clay, which masks the presence of water. This paper describes the analysis of sub-bituminous coals in Magallanes-Chile. The main coal seam components are: coal, clay, secondary quartz and water. An interpretation system using the density log, gamma ray, sonic and microlog, based on rho/sub B/-GR and rho/sub B/--Δ/sub T/ cross plots, permits to know the weight percentages of the following elements: total carbon, ash, moisture, which form the main local coal parameters. Empirical relationships permit us to obtain also the heating value and an estimate strength index to elastic-dynamic forces. The results obtained agree within 3 percent with the Laboratory cores analysis. The method is processed through a sequence of simple computer programs for IBM-360

  18. Nonparametric Analyses of Log-Periodic Precursors to Financial Crashes

    Science.gov (United States)

    Zhou, Wei-Xing; Sornette, Didier

    We apply two nonparametric methods to further test the hypothesis that log-periodicity characterizes the detrended price trajectory of large financial indices prior to financial crashes or strong corrections. The term "parametric" refers here to the use of the log-periodic power law formula to fit the data; in contrast, "nonparametric" refers to the use of general tools such as Fourier transform, and in the present case the Hilbert transform and the so-called (H, q)-analysis. The analysis using the (H, q)-derivative is applied to seven time series ending with the October 1987 crash, the October 1997 correction and the April 2000 crash of the Dow Jones Industrial Average (DJIA), the Standard & Poor 500 and Nasdaq indices. The Hilbert transform is applied to two detrended price time series in terms of the ln(tc-t) variable, where tc is the time of the crash. Taking all results together, we find strong evidence for a universal fundamental log-frequency f=1.02±0.05 corresponding to the scaling ratio λ=2.67±0.12. These values are in very good agreement with those obtained in earlier works with different parametric techniques. This note is extracted from a long unpublished report with 58 figures available at , which extensively describes the evidence we have accumulated on these seven time series, in particular by presenting all relevant details so that the reader can judge for himself or herself the validity and robustness of the results.

  19. Leveraging Call Center Logs for Customer Behavior Prediction

    Science.gov (United States)

    Parvathy, Anju G.; Vasudevan, Bintu G.; Kumar, Abhishek; Balakrishnan, Rajesh

    Most major businesses use business process outsourcing for performing a process or a part of a process including financial services like mortgage processing, loan origination, finance and accounting and transaction processing. Call centers are used for the purpose of receiving and transmitting a large volume of requests through outbound and inbound calls to customers on behalf of a business. In this paper we deal specifically with the call centers notes from banks. Banks as financial institutions provide loans to non-financial businesses and individuals. Their call centers act as the nuclei of their client service operations and log the transactions between the customer and the bank. This crucial conversation or information can be exploited for predicting a customer’s behavior which will in turn help these businesses to decide on the next action to be taken. Thus the banks save considerable time and effort in tracking delinquent customers to ensure minimum subsequent defaulters. Majority of the time the call center notes are very concise and brief and often the notes are misspelled and use many domain specific acronyms. In this paper we introduce a novel domain specific spelling correction algorithm which corrects the misspelled words in the call center logs to meaningful ones. We also discuss a procedure that builds the behavioral history sequences for the customers by categorizing the logs into one of the predefined behavioral states. We then describe a pattern based predictive algorithm that uses temporal behavioral patterns mined from these sequences to predict the customer’s next behavioral state.

  20. Advances in complex reservoir evaluation based on geophysical well logs

    Energy Technology Data Exchange (ETDEWEB)

    Fertl, W.H.; Sinha, A.K. (Western Atlas International, Inc., Houston, TX (USA)); McDougall, J.G. (Western Atlas Canada Ltd., Calgary, AB (Canada))

    1988-09-01

    The matrix of reservoirs having complex lithologies, cause different density, neutron, and acoustic responses. Therefore the lithologies and effective porosity of reservoirs can be determined by using various crossplot techniques on data collected from two of these logs. The Complex Reservoir Analysis program (CRA) computes lithology, porosity, water saturation and relative permeabilities in formations with interbedded limestone, dolomite, and anhydrite. Porosity options include crossplot and individual log response techniques. Corrections for light hydrocarbons were applied. In solving for porosity and mineral volumes, sand, limestone, dolomite, and anhydrite lines were defined on either density/neutron or neutron/acoustic crossplots. Four additional mineral lines were specified. Incorporation of Pe data from the Z-Densilog provided a significant advance in evaluating complex reservoirs via the Z-CRA analysis. The classic reservoir evaluation program CLASS, was used to perform both minerals and shaly evaluation based on density, neutron, resistivity, and natural gamma ray spectral measurements. Computations included total and effective porosities, fluid saturation distribution based on the Wasman-Smits model, productivity indices, and volume and distribution of clay minerals. Additional computed formation parameters included log-derived cation exchange capacity and hydrogen index of dry clay matrix to determine the type and amount of smectite, illite and chlorite/kaolinite present. Canadian field experiences was used to illustrate and support the techniques described. 11 refs., 11 figs., 6 tabs.